The BA Series Mounts are designed to mount high-performance optics onto your Bolt Action rifles with Picatinny Rail Scope Bases. The 1″ & 30mm versions have a center line height of 110%. 34mm models offer push-button fit for either aluminum or steel rails, while 35 mm and 36-inch long scopes can use the standard mounting hole pattern at either end, which measures 125 mils +/- .0015″. This interface ensures positive engagement on both spec positions and specs ones, so you don’t need specialized tools!