AR15/M4 Pistol Tube Kit Includes: 

(1) Receiver Extension Buffer Tube, 1.19" Pistol W/Quick Detcah Socket. Billet Aluminum
(1) Nut, Castle Extension Receiver Tube
(1) AR15/M16 Aluminum Receiver End Plate, QD - Thin Profile
(1) Enhanced Spring, Recoil Buffer, Action, Carbine
(1) Standard Buffer, Recoil, Carbine

Made in USA

*All Damage Industries QD Sockets are guaranteed to work with USGI socket dimensions