This is an easy to use jig for installing Ed Brown beavertail grip safety. This heat-treated tool slips into the frame through the thumb safety hole and allows you to make the .250 radius cut on each side of the frame perfect the first time, even if you only have simple hand tools to work with. The jig is heat-treated super hard so hand filing right up against it is okay. The buttons screw together and hold themselves on the gun for easy installation. It is perfect for gauging as well as fine finishing and has great value as a reusable professional tool. Complete installation instructions included.