Fotasy EF42A Fotasy AF-Confirm M42 42mm Screw Mount Lens for Canon EOS EF Camera Adapter This adapter allows users to use M42 Screw Mount lens to Canon EOS camera body The adapter is with electric chip, it will confirm whether the object is in focus. When the manual focus is correct, it "BEEPs" and focus light in the viewfinder lights. Please note user can only use the M42 lens manually. Auto Focus is not allowed. The function of the chip is to confirm whether focus is correct only. Work with Canon DSLR 6D 5D Mark III II 7D 60D 50D 40D 700D 650D 600D 550D 500D 450D 400D 350D Rebel T4i T4 T3i T3 T2i T2 SL1 etc. Fotasy is a registered trademark