Polymer fin brace lightweight buffer and a carbine 5-piece, 6 position buffer tube kit for AR-15 patterned rifles. Buttstock features: Supports Mil-Spec Buffer Tube Easy push button quick release. Trigger lock type adjuster 2 carry strap attachment slots Buffer Kit Incudes: 3oz Carbine Recoil Buffer 6 Position Mil-Spec Buffer Tube (Machined & Anodized in the USA) Castle Nut / Locking Ring Buffer Recoil Spring Receiver End Plate