Mission First Tactical TMARCKRS: The Tekko Metal AR Carbine KeyMod Rail System replaces the carbine 7\" plastic factory handguard in minutes and requires no gunsmithing or special installation tools. Drop in, screwless, installation means no permanent alterations need be made to the rifle. The unit is held in place by the Delta ring and handguard cap. KeyMod attachment system provides secure mounting for MIL-STD 1913 Picatinny rail attachments and accessories such as vertical grips, lights, lasers, bipods and other rail mounted kit.