Our 3" long barrel vise jaw pads are a 2-piece set and work great with any diameter barrels, tube, pipe, Etc. They also work exceptionally well with flat stock. These are made from non-anodized "dead soft" 6061 aluminum billet so that you will get a better grip on the barrel and not mar the barrel's finish. These are made to fit most barrel diameters. They drop into your vise for clamping, are very easy to use, and grip the barrel so you can install end-of-barrel accessories, clean the bore and chamber, or perform other maintenance. This is a must-have for the firearm enthusiast. They will also work on slightly tapered barrels (the chamber area on most rifles is not tapered). These are "U" blocks (not "V" blocks). These are machined for a 3/4"/19mm diameter barrel; a smaller barrel will be gripped on "flats" of the larger radius, while a larger barrel will be gripped by the edges of the radii. Forget those welded, screw together clamps; use these instead. No wood blocks or split bushings, spacer, or sleeves here. You can clamp the action on the flats and the barrel in the groove. -- INSTRUCTIONS: Simply clamp down with your bench vise and the barrel won't spin (5" minimum bench vise for best results). -- LIFETIME GUARANTEE -- DESIGNED, DEVELOPED, AND MANUFACTURED IN THE USA.