TacFire® official product. This buffer installs between bolt or bolt carrier and whatever the bolt or bolt carrier stops against when the bolt is fully retracted during firing (installation location varies with the specific firearm) * Buffer absorbs the shock from the action operating, rather than having metal to metal contact at the end of the bolt travel * Service life of the buffer is 800 to 1,000 rounds * Buffer will not be damaged by oils or solvents