This fixture allows modification of the angle to give the precise trigger pull desired. It uses special adapters that allow positioning of the sear or hammer at a precise angle. Once the part is in position, an Arkansas or India stone is set on top of the included roller guide to stone the mating surfaces on the hammer or sear for a lighter, crisper trigger pull. As an added bonus, the fixture is drilled to hold six of the most common hammer and sear pins in the same alignment as they are in the gun allowing the gunsmith to check sear engagement outside of the firearm. This fixture requires a different adapter for each firearm (sold separately). For best results, a small clamp can be used to hold the part against the fixture. Package includes fixture, allen screw, two thin metal pins, one thick metal pin, Thin pins are inserted into the top of the guide roller, the thick pin is inserted into one of two holes toward the left side of the fixture at the top. These pins are intended to act as guides for the stone (no stones are included), The fixture is intended to be used with an adapter for a particular firearm (sold separately), The allen screw and wrench are used to attach the firearm adapter to the left top of the fixture - the hole shown in the photo, Extensive instructions are included on how to set up and use this fixture