Warne Vapor rails are designed to offer shooters an affordable and reliable mounting platform manufactured for your specific firearm. The V488-20MOA offers 20MOA of elevation built in for longer distance shooting. - Fits: Winchester XPR Short Action w/8-40 screw receiver. - Precision CNC machined from 6061/T6 aluminum - Mil-Spec hardcoat anodized finish for abrasion and corrosion resistance. - Self centering tapered T-15 Torx screws. - Fits Picatinny & weaver style rings and are NATO-STANAG compatible. - 20MOA - Tapered 8-40 Screws