Watchtower Firearms CMB 5.56l Flat Faced DLC Black CMB-556-FDLC. Available in 5.56 NATO. Stainless in 316SS all others in AISI/SAE 4140 low-alloy steel. Weight - 2.55 oz Length - 2.25" Thread - 1/2"-28 UNEF Please allow 7-10 days for shipment...