The Multi-Purpose Double Dovetail Rail by Really Right Stuff was specifically designed for use with medium to large format cameras as well as some telephoto lenses. Features: Double dovetail rail accepts Arca-Type clamps on the top and bottom Includes two 3/8"-16 screws Use as a camera body plate for some medium and large format cameras Use as a lens plate for any foot with 3/8"-16 socket that does not exceed 4.75"/ 122mm Optional MPR-C flange can be installed in eight different positions to prevent twisting 4.3"/ 109mm slot length for adjustability Really Right Stuff Multi-Purpose Double Dovetail 6"/152mm Rail w/(2) 3/8"-16 Mounting Screws RRS-9000449