This Vltor Lightweight H1 A5 Recoil System Buffer is a high quality component that can be used to tune the recoil impulse or cyclic rate of an AR-15 rifle equipped with the Vltor A5 Recoil System. The lighter weight of the H1 buffer could be beneficial for a rifle that is "undergassed" or that is experiencing short stroke cycling issues, as well as a method to increase the cyclic rate or lighten perceived recoil when used in tandem with an adjustable gas block and properly tuned. The Vltor A5 H1 Buffer weighs 4.56 oz. Notes: This buffer is designed specifically for use in the Vltor A5 Receiver Extension Buffer Tube, and will NOT fit in a regular AR-15 carbine or rifle tube. Attempting to use this buffer in a standard length AR-15 carbine or rifle buffer tube Could Result in Damage to the host firearm.