By adding this IKELITE DL HOUSING SHUTTER TRIGGER EXTENSION, you will move the shutter lever closer to the right-side grip handle for easier access. The convenient accessory is compatible exclusively with models that feature curved levers, including the Dry Lock (DL) and Four Lock (FL) Port Mount versions of the Housing for Canon EOS 5D Mark III, 5D Mark IV, 5DS, or 5DS R, as well as the DL and FL versions of the Housing for Nikon D500. A hex key is included for tightening and loosening the extension.