To compliment our "Ring-Of-Steel" Action Wrench System, we've developed the only professional-quality Barrel Vise that will positively clamp and keep even the tightest barrel from turning during removal. Machined from solid steel for increased durability to service the barrel installation and removal needs of any gunsmith for years and years. Our exclusive, four cap screw system and the extra-wide design generates so much holding force, Brownells Barrel Vise must be firmly bolted to the stoutest bench or immovable base to fully realize its greatest potential. Aluminum, split barrel bushings come in eight different hole sizes and one, special, pre-machined bushing to make this universal Barrel Vise system the very first choice of professional gunsmit hs. Steel Bushings provide years of service, plus have the necessary clamping power to break loose the tightest barrels. Aluminium Bushings give exceptional holding ability without marking your barrel. Allen Head Bolt Kit - ½"-20 tpi x 2" long. Used to hold Top and Bottom Blocks together. Kit includes four bolts and the correct, 3⁄8" Allen wrench for these bolts.