The primary purpose of this accessory is to help users pull their rifle firmly into their shoulder, enhancing control and mitigating recoil. The Hand Stop can also function as a barricade stop or be reversed and positioned at the front of the handguard to prevent the support hand from slipping off. Its size and profile are designed to accommodate a wide range of hand sizes without being overly bulky. The Arisaka Hand Stop for Picatinny rails features a unique recoil lug that extends from within the part, ensuring a secure, rattle-free fit. The recoil lug and its associated mating screw are captured and will not fall out when the Hand Stop is removed from the rail. A CNC-engraved rotation direction indicator assists in tightening or loosening the recoil lug. Installation requires a 7/64" Allen wrench and should be torqued to a maximum of 15 inch-lbs.** Requires a 7/64" Allen wrench for installation (not included). Maximum torque: 15 inch lbs.