This Gun Star Picatinny 137mm adapter/base features recoil resistance, heat treated steel with a blued finish, and is guaranteed to return to zero after remount. This base has a very low mount, 10 picatinny recoil grooves, and is compatible with all guns with a Blaser R93, R8, LRS2, K95, or S2 saddle mount system. Gun Star® We take pride in precision Gun Star Ltd. Gun Star Picatinny 137mm adapter/base for Blaser GS-Blaser-6