6061 T6 aluminum construction CNC machined Hard coat anodized finish Lightweight Easy to install Fits M4 style of AR-15/M16 handguard Attaches to existing handguard 4 attaching slot head screws No permanent modifications to firearm for installation 1913 Mil-Spec rails 3 detachable rails 6 rail location configuration Ventilation gap between rails and handguard Does not interfere with tactical sling Have you been researching accessory rails for your M-4 but don't want to add more weight to your existing weapon? The Samson Modular Accessory Tactical Rail may be your answer. The MATR is CNC machined Mfg: Samson Manufacturing Corp SPECS: 6061 T6 aluminum construction, CNC machined, Hard coat anodized finish, Lightweight, Easy to install, Fits M4 style of AR-15/M16 handguard, Attaches to existing handguard, 4 attachment slot head screws, No permanent modifications to firearm, 1913 Mil-Spec rails, 3 detachable rails, 6 rail