The Precision Hardcore Gear Tru Level Picatinny Scope Mounting Base fits Winchester Model 70 Long and Magnum action rifles. The Tru Level is machine housed in the Picatinny base, protecting it from being bumped out of level. When using this base your level and scope eye piece are in the same sight picture, allowing you to check the level while aiming without having to raise your head from the shooting position.