American made, lightweight alloy scope mounts; Fully CNC machined; High-grade lightweight aircraft aluminum; Integrated scope ring and base design; Lapping not required; Designed to fit Winchester model 70 standard caliber action rifles with rear hole spacing of .860 inches; Standard calibers include but are not limited to: .223 Rem, .243 Win, 25-06 Rem, .264 Win Mag, .270 Win, .30-06 Sprld, .300 Win Mag, .308 Win, .338 Win Mag; Sold in pairs; Includes mounting screws and wrench, (6-48 Screws OR 8-40 / T-15)