Power Custom's BlackJack Recoil Buffer will reduce recoil impulse and prolong the service life of your firearm. This is accomplished by stopping the bolt from directly contacting the receiver. This abrupt transfer of energy can affect zero on scoped rifles. The AR-15 Recoil Buffer is manufactured from an advanced polyurethane that will decelerate the bolt more gradually, reducing the felt recoil and allowing for quicker set-up for the next shot. Installation is a breeze. You can feel the difference the first time you shoot it.