Prevent camera shake for super telephoto shots, macrophotography, and bulb exposures | Works just like a shutter button, enabling halfway or complete pressing | Shutter-release lock | 2.6-foot (80 centimeter) cable | Compatibility-- EOS 10D, EOS 1D Mark II N, EOS 1V, EOS 20D, EOS 20Da, EOS 3, EOS 30D, EOS 40D, EOS 50D, EOS 5D, EOS 7D, EOS D30, EOS D60, EOS-1D, EOS-1D MARK II, EOS-1D Mark III, EOS-1D Mark IV, EOS-1Ds, EOS-1Ds MARK II, EOS-1Ds Mark III