Fuel Filter Fittings Stainless Steel BOOSTER LOCK OUT Bushing 0.89 inch diameter for 1.1875x24 Booster

This lock out is designed to allow your booster to work on semi-automatic equipment. Like when you are using a 5/8x24 booster, simply change out the spring in your booster and replace it with the lock out. This bushing is used in place of the booster spring to "Lock" the booster in the seated position. This allows proper use on fixed semi-automatic equipment caliber carbines like the Colt AR15 in 9mm or the Kriss Vector like the Walther P38 that have fixed semi-automatic equipment..syi