The Radical Firearms 10.5″ HBAR profile 300BLK is a complete MIL-STD upper ready to drop on any MIL-STD lower Receiver. Perfect for the novice or advanced shooter wanting to finish out that build and hit the range. Built with the 10″ RPR 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.