DNZ Products Game Reaper Tikka 1 Inch T3 Medium Height Scope Mount fits right and left hand firearms. Base screws are 6-48 X 1/4? long. Ring screws are 6-40 X 5/8? long. Both screws use a 7/64? Allen wrench. All T3 actions are the same length. Outside to outside of rings is 4.08?. Standard rings have 2 screws per ring and rings are .63? wide. Tactical rings have 4 screws per ring and are .