SPECS: 5/8" (15.8mm) wide. Heights measured from top of base to center of ring. TSR - 7075-T6 Aluminum black, hard anodized to Mil-A-8625 standards. TSR "W" Series - 1215 alloy steel, Mil-C-13924 oxide finish, matte black. 1" - Low: .785" (19.9mm). Medium: .985" (25mm). High: 1.185" (30mm). 30mm - Low: .925" (23.5mm). Medium: 1.075" (27.3mm). High: 1.225" (31.1mm). 34mm - Medium: 1.185" (30.1mm). High: 1.435" (36.4mm).