Introducing the U.S. Ballistics Tactical Bolt Knob. The knurled texture delivers a distinct tactile feel and added grip when cycling the action. The 5/16"-24 standard thread fits most bolt handles. This bolt knob is the perfect addition to give your rifle that custom look and feel. Features:Knurled Gripping SurfaceEasy Bolt ManipulationComfortable Tactile Feel5/16"-24 Thread1.5" Long0.875" Diameter