The Kirk BL-Mark4 L-Bracket is a one-piece right-angle bracket which fits the base of your Canon EOS 1D Mark IV digital camera. It allows easy access to its side hatches which contain the battery pack, I/O ports or wireless transmitter. With the BL-Mark4, you can quickly release, turn and remount your camera for either a horizontal or vertical shot. It works well when you're using shorter macro, wide-angle and tilt-shift lenses.
The bracket must be used in conjunction with Arca-style Quick Release platforms such as ball heads or Kirk Enterprises Quick Release clamps and a camera plate (not included).