M-LOK FITS AR-15
FEATURES:Inside diameter 1.3" Outside diameter 1.5"Overall length: 10.5"6061 Aluminum Type 3 Hard Coat AnodizedContinuous MIL-STD 1913 Picatinny Top railTwo Integral Anti-Rotation QD Sling SocketsBarrel nut and barrel nut wrench includedWeight: 9.0 ozMade in USA