The Radical Firearms 7.5″ M4 profile 5.56mm is a MIL-STD upper ready to drop on any MIL-STD lower Receiver. Perfect for the shooter wanting to finish out that build and hit the range. Simply add your BCG, charging handle and you are ready to go. Built with our 7″ FCR free float rail system for increased accuracy and keeping your hands cool. No matter what your style of shooting is, Radical Firearms has you covered.