Chad Wallace

July 12, 2026

Optics, review

Primary Arms SLx 1X MicroPrismT

Chad Wallace

July 12, 2026

Optics, review

Primary Arms SLx 1X MicroPrismT

With RDB T-Dot reticle

If you have read any of my previous reviews, you know I am a fan of 1x MicroPrism optics. Primary Arms has updated their SLx line of MicroPrisms. These new prism optics have standardized mounting footprint. One of these new prisms has a Red Dot Bright (RDB) reticle. That particular one is the Primary Arms SLx 1X MicroPrismT with RDB Illuminated T-Dot Reticle.

As with all of the Primary Arms MicroPrisms, they come with everything needed. You get scope caps, wrenches, a battery, and a way to mount it. The “T” in MicroPrismT designates the new mounting footprint for these prism sights. “T” is for the standard T1/T2/H1 Aimpoint Micro mounting footprint. This allows the SLx T prism to attach to any of the mounts that use this footprint, and there are a ton of them. Besides that, the SLx MicroPrismT comes with a very nice 2.26 inch high mount. This is one of those “heads up” style mounts and is very usable.

New in the SLx MicroPrismT is the T-Dot reticle. It is called a “T-Dot” because the lines in the reticle form a T shape. And guess what, where those T lines almost intersect, there is a 2 MOA center dot. It is a super simple and fast reticle. There are no marks for hold overs or bullet drops, making it even more like a red dot. The SLx MicroPrismT also has the new RDB dot, or “Red Dot Bright”. Since this is the T-Dot reticle, only the center dot is illuminated with the RDB system. When Primary Arms says “Red Dot Bright”, it really is that bright.

In the adjustment department, nothing has changed over the original SLx Prisms. You still get a diopter to adjust the clarity of the reticle to your eyes. The Brightness setting is still combined with the battery knob. So the battery sits inside the brightness knob. It still has 13 levels, with the bottom 3 being used for night vision. The top settings are now brighter thanks to the RDB system. The brightness knob is pretty stiff with not great detents. But you really do not need to worry about that since Primary Arms did include their “Autolive” system. So the reticle will turn off automatically and then turn back on when it senses motion. Reticle adjustments are the same 1 MOA clicks as in previous SLx prism optics.

Primary Arms has not changed the glass quality on the new T prisms, but they didn’t need to. Looking through the SLx MicroPrismT is still super clear. It is still a true 1 power reticle, so what you see is exactly what you see through the prism. The SLx T-Dot is also an etched reticle. This has a couple of advantages. One is that the reticle doesn’t need power to be seen. Of course you don’t get that red dot glowing, but you still have something to aim with, unlike a regular red dot. The next advantage is that people who don’t see red dots clearly, will usually see etched reticles clearly. The last advantage to the SLx line of prisms is that they can use Back Up Iron Sights (BUIS) and/or a magnifier.

I ended up mounting the new SLx MicroPrismT on a Foxtrot Mike Mike-15 Gen 2. It replaced a regular red dot that was on the rifle. I really like 1x prisms on AR style pistols, so the SLx fit the bill perfectly. I really like the T-Dot reticle, not just because it is bright, but because it just works. I would prefer more of a circle dot reticle where just the center dot illuminates, but they didn’t ask me. One of my favorite aspects of the Primary Arms prism optics is their incredible eye relief. They state 2-7 inches, but it is essentially anything. This makes it work great for speed and odd positions because you don’t have to worry about where your eye is in relation to the optic. On that note, the MicroPrismT comes with a 2.26 inch high mount. It is a nice mount, but too high for my liking on the Mike-15. Good thing it uses T1/T2 mounts so I can get whatever height I want.

The Primary Arms SLx 1X MicroPrismT is a really nice 1x prism. The reticle is simple to use. Being an etched reticle helps make it super clear for people with eye anomalies. The industry standard mounting footprint gives you plenty of options, especially if you don’t like the supplied 2.26 mount. Lastly, that RDB lets you see the dot in any lighting conditions. If you are looking for a true 1x prism, I would check out the new Primary Arms SLx 1X MicroPrismT with RDB Illuminated T-Dot Reticle. With the performance you get from the Primary Arms Prisms, you can’t beat their value.

Firearms Insider Reviews - Key Points

Claim to Fame:

1 power prism optic with a simple to use, daylight bright reticle

Target Market:

Anyone wanting an etched reticle 1 power optic that can be seen in direct sunlight

Features, Benefits, and Specifications of this product:

H1/T1 optic footprint
Magnification: 1x
Objective Lens Diameter: 17mm
Eye Relief: 3.6" (Usable Range: 2" to 7")
Exit Pupil: 15.6mm
Field of View: 76.5 ft @ 100 yards
Length (w/o lens covers): 2.48"
Weight (with battery, w/o lens covers): 5.5 oz
Illumination: 13 settings (3 NV-compatible), Red Dot Bright
Reticle: T-Dot (etched glass)
Click Value: 1 MOA
Total Elevation/Windage Adjustment: 120 MOA each
Battery: 3V CR2032
Mount Footprint: H1/T1 micro dot compatible
Construction: Aluminum alloy with hard coat anodizing
Waterproof: IP67 / Nitrogen purged / Dustproof
Includes: 2.26" mount

What other aesthetic options or finishes are available?

Both red and green in ACSS Cyclops and Gemini reticles. These are not Red Dot Bright (RDB) reticles

What others are saying?:

5 out of 5 stars on Amazon

Great optic, no low mount actually included

Awesome optic. Insanely crisp reticle for someone with astigmatism. Did not think I would ever see a reticle be so clean. Great glass and great mount as well. One thing to know is that the info here on Amazon, the packaging, and the manual all state that a low mount is included. This is incorrect, as only the high mount pictured is included. This info is posted on PA's webpage for this product. I just wanted to let anyone looking at this optic know that in case they were counting on the low mount. Five stars for me as I didn't need the low mount and the optic is otherwise exactly as described. Excellent optic for an excellent price. Would recommend, if you don't need the low mount that is.

Link to other reviews:

Athlon Outdoors

Price point:

MSRP = $279.99

Retail = Same

I need it now! Availability:

Primary Arms or Amazon

Our Rating:

Pros:

Super Bright
Clear reticle
Industry standard T1/T2 footprint
Great Eye Relief
Can be used with BUIS and magnifiers

Cons:

Smallish objective lens
Stiff brightness knob

Score: 8.50 Great

Favorite Link: Primary Arms SLx 3x Prism review

Chad Wallace

May 17, 2026

Optics, review

Primary Arms PLx 1-8x24 RDB

Chad Wallace

May 17, 2026

Optics, review

Primary Arms PLxC

1-8x24 RDB LPVO Review

The PLx series from Primary Arms Optics is their top tier “premier” optic line. Recently they updated their PLx Low Power Variable Optics (LPVO) with “Red Dot Bright” illuminated reticles, or RDB as they call it. They sent over one of the PLx 1-8x24 RDB with the ACSS Raptor G2 reticle. This is their first focal plane (FFP) reticle for 5.56/308 that has ranging capabilities. Is it perfect? No, but it does have some fantastic features.

When you first see the Primary Arms PLx 1-8 you notice it. The lines are very sleek. It is not a target scope with huge turrets. Which is what you would expect from a LPVO. It is compact when compared to some other FFP optics in this tier. It is also fairly lightweight. All the controls are easy to get to and function better than expected. Then there is the super clear glass.

First, I am jumping right into the reticle. The PLx 1-8 has 2 different reticle options: The ACSS Griffin MIL G2 and the ACSS Raptor 5.56/.308 Yard G2. I opted for the ACSS Raptor reticle, the Griffin is more of a standard MIL reticle and I wanted something where I didn’t have to think too much for bullet drop. Both are FFP reticles and get larger when you zoom in. This is because all markings on the reticles stay the same actual size for ranging and bullet drop compensation.

The ACSS (Advanced Combined Sighting System) Raptor reticle was designed primarily for 223/5.56 rifles, but it also will work on 308 rifles. I will explain it for 5.56. The Raptor is a Bullet Drop Compensating (BDC) reticle that also does range estimation and has MIL markings. Pointing toward the center reticle are 3 solid lines, these can only be seen between 1x and 2x. When zoomed in past that, you only see the inner reticles. There are then MIL marked lines toward the inner most BDC reticle. The inner BDC reticle is where all the magic happens.

The Raptor BDC part of the reticle allows one to range targets and adapt for wind. In the very center is the horseshoe chevron reticle. The horseshoe is roughly 2.5 MIL’s in diameter and then has a small center chevron (open triangle). You sight in at the top point of the chevron. This gives a very precise aiming point. The BDC marks are then below the chevron marked with 4,6, & 8. These numbers are in yards for bullet drop. The bottom of the chevron would be 200 yards and the top vertical stadia mark would be 300. This mark is also at the bottom of the horseshoe. There are wind holds, or lead dots, for 5, 10, & 15 MPH at the BDC ranges. Horizontal to the horseshoe are 3 more dots. These are for leading a target also, but they are 3, 6, & 9 MPH which corresponds to a human's walk, jog, and run.

Simplified ranging can also be done with the ACSS Raptor reticle. In the reticle, on each side going toward the outside, are vertical lines. These lines get larger as you move toward the outside of the reticle. There are 5 lines with a number on every other one. The numbers designate a range in hundreds, so the #6 represents 600 yards. These lines fit an average height person. So if the person fits perfectly in the #4 line, you know they are at approximately 400 yards. To take the ranging one step farther in the Raptor reticle, there are also width ranging lines that run down the vertical BDC marks. These horizontal small lines are used to measure a 18 inch wide target, like a USPSA one. Or the average width of a human torso. Essentially you use it the same way as the height ones. Fit the target in the proper line, say the #6 line, and you know the target is at approximately 600 yards. The ranging is actually pretty easy, once you get the hang of it.

Now that you know about the reticle, let’s adjust it. The PLx comes with capped turrets. This helps with the low profile of the 1-8. The turret covers are about 1.5 inches in diameter and have pretty sharp knurling on them. So it is easy to unscrew them, even with thick gloves on. Inside those covers are the turrets themselves. They are about 1.375 inches in diameter with aggressive texture on the top to aid in adjustment. Both windage and elevation turrets adjust in 0.1 MIL increments.and go 10 MIL’s per complete revolution. The windage knob has numbers with both and R & L so you know which way you went. Of course the elevation knob has numbers 0-9, the 10 being the zero again. Both knobs have 3 tiny screws that hold the knobs in place. Once you have sighted in the optic, loosen the screws on the turrets and adjust it to the zero position, then re-tighten the screws. Primary Arms also includes a target style elevation turret. So if you want an adjustable turret without having to take off the cap, you can install it. I say target style because there is no cap, the target turret is still low profile in design. The actual adjustment clicks on the PLx are fantastic. Not only are they solid, but there is very little play when turning them from click to click. They aren’t as audible as you might think, but since they are super tactile, I do not care. The turret adjustments are steel on steel gears. This is one thing that sets higher tier optics above the cheaper ones. Plus they don’t wear out as quickly and return to zero with no error.

The PLx 1-8’s red illumination is bright. That is why it has the RDB label, it stands for “red dot bright”. I can attest that with the new technology Primary Arms is using, this reticle is super bright. Yes, it can be seen in direct sunlight, easily. With the reticle at 1x, it really can be used as a red dot and even kind of looks like one, because the horseshoe ends up looking like a bright red dot. When you zoom in to 8x, it is still just as bright, but does have some problems. If you look at all the info on the RDB, it shows only the horseshoe and chevron being illuminated. The problem with high brightness and magnification is that the small lines and numbers become tiny illuminated dots. It muddies up the reticle in my opinion. Turning down the reticle's brightness does help. I have a non RDB Primary Arms LPVO that does this a little bit also, so it’s not just the PLx line. Along with the illumination, the PLx 1-8 also has Primary Arms’ Autolive feature. This is their shake away auto on/off for the reticle. It helps save battery life and works fantastic. The battery is housed inside the brightness knob. There are 10 brightness settings with an off position between each one. Each setting has a positive detent to keep it in place.

How clear is the PLx 1-8? I'd say near perfect thanks to the Japanese ED glass that is used. Light transmission is also fantastic. The clarity is where you really notice the quality of the glass. I can't really explain it, it's just clear with no edge distortion. Eye relief is pretty decent and forgiving, even at 8x. I can look through this optic without the eye strain I get from lower tiered optics.

The PLx 1-8 also has a nice magnification adjuster. It is nicely knurled and super smooth to adjust. It also comes with a removable throw lever. These throw levers can be swapped for shorter, taller, or folding ones, but they have to be purchased separately. Either way, the throw lever on the magnification ring works nice and is the perfect height.

I ended up installing the PLx 1-8 RDB on a Flat Dark Earth 16 inch AR build. This AR has a bunch of high quality parts on and in it, so I figured it would be a great host for the PLx. Also having the 16 inch barrel puts the optic in its sweet spot for the BDC. Primary Arms also sent one of their 2.04 PLx mounts for the scope. I wasn’t sure if I would like the 2.04 mount at first, but it is kind of nice. Okay, back to the PLx 1-8. I do like that this optic is made in Japan and not China. Japan has some of the clearest optic glass around and it really shows in the clarity of the PLx. I also really liked that the PLx weighs just over a pound. It would be nice if the PLx 1-8 could have a zero stop in the turret. It may not be that “type” of scope, but a zero stop would be a good addition. The anodizing color is close to FDE, but looks more bronze colored to me. This is just another reason why we have 50 shades of FDE. The bullet drops from the Raptor reticle seemed close enough for me. This is more of a fighting optic for me, not a precision one, which is why I like the ACSS Raptor reticle. Of course, having the autolive illumination makes the LPVO ready whenever you are. The Primary Arms PLx 1-8 is a fantastic optic with a very useable magnification range.

If you are looking for a LPVO that really does it all, check out the Primary Arms PLxC 1-8x24 FFP RDB scope. There is a good reason this thing is in Primary Arms’ Premier line of optics. It has fantastic clarity, a sunny daylight bright reticle, and can be used both as a red dot and something for distance. If you are interested, head over to Primary Arms and take a look at the PLx 1-8x24 RDB with the ACSS Raptor G2 reticle.

Firearms Insider Reviews - Key Points

Claim to Fame:

Top tier LPVO

Target Market:

Those needing a rugged, precise, super clear LPVO with useable features

Features, Benefits, and Specifications of this product:

Red Dot Bright Diffractive Reticle technology
ACSS Raptor 5.56/.308 Yard G2 Reticle
Premium grade Japanese ED glass with enhanced clarity and light transmission
First focal plane reticles stay true at every magnification
High strength 30mm tube
Easy to swap dovetail throw lever
1-8x magnification range is red dot fast in close quarters and accurate at medium range
AutoLive Motion-Sensing illumination technology
Steel On Steel (SOS®) Adjustable turrets
Adjustable illumination from Daylight bright to night vision compatible
Water proof, shock resistant, and fog resistant
Durable hardcoat anodized flat dark earth finish
Made in Japan
Battery Type: CR2032 3V Lithium
Click Value: 0.1 Mil
Exit Pupil Diameter: Low: 8mm / High: 3mm
Eye Relief: Low: 3.2 in / High: 3.7 in
Field View 100: Low: 121 ft / High: 14.6 ft
Length: 9.28 in.
Night Vision Compatible
Objective Diameter: 24mm
Total Elevation Adjustment: 100 MOA
Total Windage Adjustment: 100 MOA
Capped Turrets
Weight: 16.95 oz.
Lifetime warranty

What other aesthetic options or finishes are available?

Griffin Mil G2 reticle in black or FDE

What others are saying?:

5 out 5 stars on Optic Planet

As good as it gets

Got this on a sale and paid just under 1500 after tax and shipping. For the price, you won't find a better LPVO. This thing rocks. Got the ACSS Raptor reticle as I'm running this on a 14.5 super duty and prefer the 50yd zero and ballistic drop reticle over the Griffin. Glass clarity is superb all through magnification range. And yes, this thing is absolutely red dot bright even on 7/10 setting. Maybe at high noon on a glacier you would need to go higher than 8/10 on the illumination setting. Don't bother getting scope rings with this as you will do away with the near invisible scope feature when you're at the lower magnification settings. That is also an amazing thing about this scope: at 1x, with both eyes open, the scope itself is barely perceptible when looking at your targets. Once you get the diopter adjusted to your eye (both eyes open!) there is no noticeable shift in your view when taking turns closing each eye to see the shift.