The heavyweight buffer is used to slow down the cycle rate in AR Carbines. This slowing of the cycle rate increases rifle reliability, reduces felt recoil, and helps lengthen receiver life. By increasing dwell time, it delays unlocking of the bolt thereby reducing stress on the extractor/case rim. A heavyweight buffer also adds reliability for a shooter who is using a sound suppressor. This H-Buffer (note marking on the end) weighs 3.76 oz. versus the standard weight of 2.96 oz. Otherwise, appearance is identical to the standard weight buffer.