This Base Plate for Canon EOS-1D X Mark III from Really Right Stuff is custom designed for the Canon EOS-1D X Mark III DSLR camera. It is precision machined from a solid block of 6061-T6 aluminum and is compatible with any RRS system and most Arca-type systems. The plate features a dovetail design and anti-twist flanges to prevent twisting between the camera and the plate. This keeps your camera centered directly above the tripod's apex, which keeps your camera and lens as stable as possible. A custom machined 1/4"-20 mounting screw threads into the tripod mounting socket of your camera body, and the plate features a fully integrated QD (Quick Detach) mounting system, allowing you to rapidly mount or dismount a support strap system with a QD mounting socket.