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OPEN BOX RETURN - AT3™ PROLOK M-LOK™ AR-15 Free Float Handguard - 10” Length

OPEN BOX RETURN – AT3™ PROLOK M-LOK™ AR-15 Free Float Handguard – 10” Length


MSRP: $110.99


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90 Day No-Hassle Returns We Pay Return Shipping

We have a 90-day no-hassle return policy. We pay return shipping.

If you need to request a return, contact us at support@at3tactical.com and we will send you a return label

After 90 days, defective items will still be covered under the manufacturer’s warranty, where applicable.

Please refer to the product listing for warranty details. If you have specific warranty questions, contact us at support@at3tactical.com. We may direct you to pursue your warranty claim directly with the manufacturer.

Your satisfaction is our #1 priority

If you’re dissatisfied with your purchase, in any way, please contact us at support@at3tactical.com – we will do our best to make it right.

Fast & Free Shipping On orders over $50

You will receive fast, free shipping for all orders over $50

Shipping cost is $7.99 for orders under $50. We ship with UPS or USPS, depending on the item.

Most orders received by 1pm CST ship the same day

You will receive an email with tracking information at the time of shipment. To expedite shipping, we may ship your order from multiple warehouses. Orders placed on weekends, holidays, or after 1pm will ship the following business day.

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.

AT3 PROLOK Free Float AR 15 Handguard

This item is an Open Box Return. There may be signs of light use such as scratches or other blemishes, but is complete and in working condition.

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.

The 10″ 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
  • 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

IMPORTANT NOTEthe 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.

More Information

Full kit – includes all mounting hardware plus two M-LOK 3-Slot Rail sections – all included parts pictured below.

AT3 PROLOK M-LOK AR 15 Handguard Full kit showing all mounting hardware plus two M-LOK 3-Slot Rail sections

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)

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)

AT3™ PROLOK M-LOK™ AR-15 Free Float Handguard Night Shot

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