Designed to fit Mil-Std. 1913 scope bases, Nightforce rings are precisely manufactured to match the machined recess of a Nightforce Mil-Std. 1913 base, providing perfect alignment and accuracy. Nightforce rings are designed and produced in-house to exacting specifications from 7075-T6 aluminum with beta series titanium crossbolts and jaws. All Nightforce rings are 100% micro-radiused and honed in pairs for perfect fit of 30mm scope tubes to prevent the possibility of the rings damaging your scope. Height is from top of base to centerline of ring. Available in Low (.885”), Medium (1”), High (1.125”), Intermediate (1.265”), Extra High (1.375”), and Extreme Heights (1.5”).