Magpul Industries MOE Slim Line Handguard, Fits AR-15, Mid Length, Polymer Construction, Features M-LOK Slots, Black MAG551-BLK The MOE SL Hand Guard for AR15/M4 firearms with mid-length gas system and A2 font sight provides modular flexibility with M-LOK accessory slots in a lightweight" sleek" cost effective design. Designed with versatility in mind" M-LOK slots at the two" six" and ten o'clock positions allow the attachment of optional Picatinny rail sections and other accessories for mounting tactical lights" slings" grips" etc. Reinforced" heat-resistant polymer construction provides durability without the weight and expense of an aluminum rail hand guard. A large front extension and lower lip protects the user from the hot front sight gas block assembly and maximizes useable hand guard length.