RPM Ruff's Precision 30MM Scope Rings30mm precision riflescope ring set with built in co linear bubble level. Built in level is visible from the shooting position with the shooters' non dominant eye for quick reference prior to the shot. Level significantly aids in accurate scope mounting by giving reference to the cant of the rifle during the scope mounting process while eliminating the need for multiple small levels and balancing acts! 6061 T6 aluminum ring body and cap 303 stainless