The kit contains
T6 6061 Aluminum A2 Buffer Tube
Rifle Length .308 Cal Chrome Buffer Spring
A2 .308 Cal Buffer,
but does not include the castle nut or end plate.
Mark H.
A2 tubes do not require castle nuts, or end plate. It will screw into the lower receiver until it seats. Your stock of choice (A2, Magpul PRS, etc....) will then mount against the lower receiver as well. If you want a castle nuts and end plate use an A5 tube.