SABRE DEFENCE 16in M4 barrel with YHM flip up front sight. 5.56mm NATO, carbine length gas system, M4 feed ramps, Vanadium steel, A2 flash hider, chrome lined bore and chamber with a 1 in 9 twist. Delta ring assembly installed. New never installed on an upper. $345 Payment with USPS money order. Buyer pays actual shipping. Insurance is optional. Please contact me if you have any questions.