This kit contains all the necessary parts to mount to your Mil-Spec dimension stock assembly to your Mil-Spec lower receiver:

• MK2 Mod 1 – T0 Buffer (weight = approximately 3.8oz)
• Mil-Spec M16A4 rifle action spring
• Mk2 Receiver Extension (approximately 3/4” longer than carbine), 7076T6, 8 position, Mil-Spec diameter
• Lock Nut (Castle) M4
• Receiver QD End Plate (include mount for QD swivel)