3.8 oz intermediate-length buffer for the BCM MK2 receiver extension and M16 rifle action spring.

The BCM MK2 Mod 1 T0 is a 3.8 oz intermediate-length buffer. BCM requires it to run with the BCM MK2 receiver extension and a mil-spec M16 rifle action spring.
Add the BCM MK2 Buffer Mod 1 T0 (3.8 oz) to your build and see how it enhances your platform.