Keep your optics locked down tight with the additional hold of Weaver's SureThread . When mounting optics, this thread adhesive helps prevent the loosening of mounting screws caused by the shock and vibrations generated from recoil. Take the time to mount your scope properly and then take the time to ensure it stays that way. Use Weaver SureThread. Product Features For use when mounting scopes and bases to assure locked-down optics Prevents shock and vibration from loosening screws Loosens easily with basic hand tools