STD Ruger American 2pc Scope Base Matte by Leupold Optics offers the STD Ruger American 2pc Scope Base in matte finish. The STD bases are forged and machined from high quality steel and finished to a beautiful sheen. These bases are constructed from high strength steel for durability and longevity. The mounts are designed by Leupold to fit the Ruger American rifle. Leupold STD mounts are windage adjustable via two slotted screws on the rear mount. Summary The STD Ruger American bases are constructed of hardened steel for exceptional strength. The STDs have rear ring windage adjustment screws and reserving the scope's internal adjustments for precise sight-in and more adjustment in the field. The rear mount is a screw mount and the front is a turn in style. These bases work with Leupold STD rings. Specifications and Features: Windage Adjustable Forged Steel Expert Finish Two Piece For Leupold STD Rings