The FR-1 Accessory Cap adds another level of customization and versatility to your set up. Its compatible with both the FR-1 Optics Mounting System and the Gen 2 Tru Lock Scope Rings. The FR-1 Accessory Cap utilizes a three-point steel dowel system secured by a single screw at a 45° angle creating unparalleled strength, rigidity, and speed for laser and Red Dot zero retention. Once installed, the FR-1 Accessory Cap can be used to attach the FR-1 Fire Control Diving Board Mount and the FR-1 Red Dot Mount. Features: Compatible with the FR-1 Optics Mounting System and the Gen 2 Tru Lock Scope RingsUtilizes a three-point steel dowel system and single screw at 45° for strength and rigidityCompatible with FR-1 Fire Control Diving Board Mount and FR-1 Red Dot Mount American Precision Arms FR-1 34mm Accessory Cap FR134CAP