NEWYI 58mm Macro Reverse Adapter Ring and Rear Lens Mount Protection Ring for Canon EOS EF Mount 58mm Filter Thread Lens this lens mount adapter allows any 58mm lens become a marco lens on camera body. when you reverse mounted your lens,installing this adapter can protect your lens rear part,including mounting part,lens part and electronic part to avoid unexpected damage and contaminate in addition,the ring have 58mm screw mount,you can attach filter such as uv,cpl and lens cap to prevent dust getting into the lens. ra-eos58 macro reverse ring adapter with 58mm male thread fits for: canon eos ef camera body reverse ring is threaded on one side to fit the filter thread of your lens, the other side has a mount like your camera lens it allows any 58mm lens become a marco lens on canon eos ef mount camera body this greatly increases the macro reproduction range screw diameter: 58mm material:anodized aluminum packing included: 1 x rear lens mount protection ring for canon eos ef ef-s mount camera lens 1 x new 58mm reverse adapter ring for canon eos camera body