Recoil Buffers protect your firearm from the shock caused by the metal-on-metal impact of the bolt or operation rod with the receiver. This impact causes felt recoil and muzzle jump, over time the metal will begin to change shape and even crack. Each buffer is made from shock absorbing polyurethane and acts as a cushion to absorb this shock. Buffers help maintain your weapon's accuracy and extend its service life. Installation is simple and requires no special tools. Protect your investment while enjoying it! *Brief instructions are included.