JP Enterprises Hammer stop block Black. These Gunsmithing Tools from JP Enterprises fit into the magazine well of your firearm. When the trigger is pulled your JP Enterprises Hammer Stop Block Part absorbs shock from the hammer and allows you to judge the trigger movement and pull weight. Avoid expensive repairs by using the JP Enterprises Hammer Stop Block Piece. Specifications for JP Enterprises Hammer Stop Block: Manufacturer: JP Enterprises Color: Black Features of JP Enterprises Hammer Stop Block: A must have for trigger installations Reliable materials Dependable construction Package Contents: JP Enterprises Hammer Stop Block Component JP Enterprises JPFC-HS: Hammer stop block Black