This is 200mm back extended Gun Star picatinny adaptor/base will give you the "over the stock" rail you've been looking for. Extending 124mm from the rear point of attachment, this base features recoil resistance, heat treated steel with a blued finish, 17 picatinny recoil grooves, and is guaranteed to return to zero after remount. This base is compatible with all firearms with a Blaser R93, R8, LRS2, K95, or S2 saddle mount system. Gun Star® We take pride in precision Gun Star 200mm Picatinny adapter/base for Blaser GS-Blaser-9