Lower Receiver Buffer Extension Kit - MIL SPEC for AR15 .223 / 5.56
- Lower Receiver Extension Buffer Tube, 6 position.
- AR Castle Nut / Buffer Tube Locking Ring
- AR Receiver End Plate
- Carbine Buffer (3 oz, 3.25")
- Carbine Buffer Spring
Use with adjustable butt stocks that are designed for Mil-Spec diameter buffer tubes (1.14"). Commercial size stocks are wider (1.17") and won't fit correctly.