These are made to hang on the steel jaws of your vise so there is no need for magnets or two more hands. These are machined for just about any diameter barrel. They drop into your vise for clamping, are very easy to use, and grip the barrel so you can install muzzle brakes, clean the bore and chamber, or perform other maintenance. This is a must-have for the firearm enthusiast or anybody with a straight or lightly tapered barrel (the chamber area on