The Troy Drop In Mid Length BattleRail is a non free floating direct replacement for all M4/M16 carbine plastic hand guards. The Troy Patented clamping design ensures absolute rock solid mounting which is unequaled in the world today. The Drop In Mid Length BattleRail provides a true optical mounting platform that increases the modularity and accuracy of the M4. No gunsmithing is required and the unit installs in less than a minute and providing true U.S. Military Specification M1913 rails at 12-3-6 and 9 o'clock. All rail systems are machined from T6061 hardened aircraft aluminum and anodized in MIL-STD Type III Hard Coat in Flat Black. Made in USA.