RUGER PRECISION RIFLE HYBRID 30 CAL MUZZLE BRAKE 5/8 - 24 NO CRUSH WASHER NEEDED - SKU: RP90590 One size suits 6.5 Creedmoor and 308 Win model RPR"s Reduces recoil by as much as 58% (depending on calibre and barrel length) contributing to improved accuracy over a longer string of fire. Brake locks into position using an easy-to-use external jam nut. Reduces noise and blast to the sides of the shooter. Installs quickly using a 11/16 box wrench or crescent wrench. Manufactured from alloy steel with a matte black finish. Threads: 5/8-24 Dimensions: 2.2" length, 1.0" diameter Weight: 3.2 ounces Made in the USA.