Compatible with Canon EOS R mount series mirrorless camera.<br />Made of brass and aluminum. Stable, precise and durable construction. Manually operated. Infinity focus allowed.<br />For heavy medium format lenses, we suggest to use with a telephoto bracket and a tripod to balance its weight when shoot.<br />Quality copper aluminum alloy precision manufacturing, ring with the camera bayonet close and smooth, the fine copper bayonet will not wear the lens, durable.<br />Lens interface with fine copper material, higher precision, easy to wear, durable.<br />Red dot mark, accurate alignment, convenient installation and disassembly.<br />Full manual control, manual focusing, aperture priority, infinity focus.<br />Please note: when using the adapter ring for the first time, please turn on the “release shutter w/o lens”option in the menu, otherwise the adapter lens will not be recognized. ">