90mm (3.5 inches) I.D. rings with three point adjustment, Delrin tips. Wt. 1.25 lbs. per set, 2 rings per set DA dovetail mounted, no tools needed. I.D. size from 1.7 inches TO 3.5 inches Ht. from top of dovetail plate to center of rings 3.25 inches Part : DR90