This fixture allows positioning of the sear or hammer at a precise angle for custom trigger pull adjustments. Once the part is in position, an Arkansas or India stone is set on top of the roller guide (included) to stone the mating surfaces on the hammer or sear. 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.