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Based on the popular M-LOK™ platform, the AT3 PROLOK Free Float AR 15 Handguard is a lightweight, durable, and customizable M-LOK handguard at an excellent price.
The slim free-float design enhances accuracy, while minimizing the weight of your rifle. M-LOK attachment slots and 2 included rail sections provide unlimited options for accessorizing your build.
With 10”, 12” or 15” lengths available, the PROLOK handguard is ideal for customizing your next AR-15 build, or upgrading an existing rifle.
Lightweight & Durable
- Unique slim and lightweight M-LOK design with M-LOK attachment points at the 3, 6, 9, & 12 o’clock positions
- Durable 6061 aircraft aluminum alloy construction – designed to take a beating
- Picatinny/M-LOK top rail perfectly aligns with AR-15 flat-top upper receivers
- Handguard screws securely onto the included steel barrel nut using steel mounting hardware to assure a secure fit with zero movement
- Backed by the AT3 Lifetime Warranty
- Easily upfit your handguard with M-LOK accessories – compatible with all M-LOK products including rail sections, forward grips, hand stops, rail panels, and more
- Available in 3 lengths (10”, 12”, and 15”) to accommodate a variety of build types
- Precision milled M-LOK and Picatinny (MIL-STD-1913) rail slots assure proper fit for attachments. Two 3-slot M-LOK-to-Picatinny rail sections included
Exceptional Fit and Finish
- Durable matte-black anodized finish resists scratches and provides an attractive surface that matches the rest of your build
- Vented design reduces weight heat from shooting
- Installation questions? Check out the installation instructions for the PROLOK handguard
IMPORTANT NOTE – the barrel nut requires a 30mm (1 3/16”) wrench (not included). Most AR-15 Armorer’s wrenches will work for this, or we recommend using an armorer’s wrench or 30mm (1 3/16”) crowfoot with torque wrench.
Full kit - includes all mounting hardware plus two M-LOK 3-Slot Rail sections – all included parts pictured below.
Note: most rifle setups will require the use of a low profile gas block that sits under the handguard.
Included in the box:
Handguard with steel barrel nut and all mounting hardware, two 3-slot M-LOK to-picatinny rails, barrel nut shims, and hex wrenches for handguard and rail sections
- Rifle Type: AR-15 (If you have a .308 AR variant, check out our AR-10 / .308 page)
- Material: 6061 Aircraft Aluminum
- Included Rail Sections: Two Aluminum Picatinny Rail Sections - 1 3/4” Length, 3 slots
- Finish: Hard-coat anodized (matte black)
- Handguard inside diameter: 1 3/8”
- Barrel nut inside diameter: 1.02” (compatible with barrels up to 1” diameter)
- Weight: BN 3.9oz
- 10" Handguard – 7.5oz (handguard only) / 11.4oz (handguard + barrel nut)
- 12" Handguard – 8.5oz (handguard only) / 12.4oz (handguard + barrel nut)
- 15" Handguard – 10.3oz (handguard only) / 14.3oz (handguard + barrel nut)
Frequently Asked Questions:
Will this fit my AR-15?
This handguard will work with the majority of mil-spec AR-15’s on the market. In most instances, it will also require the use of a low-profile gas block that fits underneath the rail.
This product will not work with non milspec upper receivers like the Bushmaster Carbon due to the non-standard barrel threads, and it is not compatible with most piston kits as they won’t fit under the handguard.
We’re always glad to verify the fit for your rifle, just contact us! And if it doesn’t fit, we are glad to return it for you. And if you’re new to AR-15, we recommend watching a couple of the videos on our installation video page to understand how the process works.
What tools and additional parts are required?
For parts - most setups will require a low profile gas block.
For tools - we recommend:
- A vise and non-marring vise block for holding the upper
- 30mm (1 3/16”) wrench - most AR-15 Armorer’s wrenches will work for this, or a 30mm (1 3/16”) crowfoot
- A torque wrench to assure you stay in the AR-15 barrel nut torque range while timing the barrel nut (30-80 ft lbs)
Have Questions About this Product?Ask Us Now
Purchased this hand guard for my new build. Looks great and fits great too! Free two day shipping is top notch! Definitely will continue to shop with AT3!
Good quality for the price.
Very pleased with my recent purchase. I recieved my order very quickly and the quality was excellent. Will be making more purchases in the future.
At first the handgaurd that I wanted was out of my stock, in a short time I was notified it was available. Great job AT3!
i had been researching the AT3 Prolok-K handguard and decided i was ready to order. But, i must have clicked on the Prolok-M model instead and that is what i received. I decided to go ahead and give it a try, not really knowing whether one was better than the other. The first thing i noticed was that the handguard mounting system was different than that for the Prolok-K (AT3 had previously sent me the mounting instructions for the Prolok-K handguard, at my request). Again, not seeing firsthand how the Prolok-K actually attached to the barrel, i don't know whether one is better than the other. But, with the Prolok-M, it was somewhat difficult to get the barrel nut tightened into just the right spot so that the top rail of the handguard was in the exact same plane as the rail on the upper. i would tighten the barrel nut, install the handguard, put in a couple of screws, see how it lined up. not right, so would remove the handguard and tighten the barrel nut a little more, install the handguard, check alignment, etc. I think i did this process 4 times before i was satisfied with the fit. It would have been nice to have videos we could watch, beforehand, on how these two different handguards are supposed to be mounted to the barrel. I like being able to know 100% for sure that what i've just done is the way it's supposed to be done. That is the only reason i'm giving 4 stars instead of 5.
Got my rail fast and in good condition. I did return my rail because the finish did not match the rest of my gun. The return process was easy and hassle free.