On Sight Armory's 15" KeyMod handguard has a continuous rail that  allows you to mount iron sights, optics, and any other accessories without additional railing sections. The Keymod system allows users to personalize the hand guard with railing sections and guide attachments. The hand protector is constructed of 606T6 aircraft aluminum & completed with a hard coat black anodizing. Has a precision bore at match the owner's barrel nut that removes any play and ensures an exact match! Installation takes a crows foot wrench for the barrel nut; standard AR-15 socket nut wrenches won't work with this particular hand guard system.
 
 
Features:
Material: Hard Coat Anodized Aluminum Handguard, 6061-T6 Aluminum Barrel Nut
Precision Bore
1913 Picatinny Continuous Top Rail
Accepts Keymod Rail Sections & Accessories 
Requires 1-1/8" Crowfoot Wrench and Medium Strength Thread Locker (not included)