Designed to fit mil-std-1913 bases , Nightforce Steel Rings are machined with a load-bearing recoil lug on a grade eight crossbolt to precisely match the machined lug of Nightforce bases for perfect alignment. Offering the performance of steel at half the weight, Nightforce Ultralite Rings are crafted from CNC machined 7075-T6 hard anodized black aluminum bodies with titanium beta series crossbolts and jaws.