Leitax is like Impossible: A company to make the impossible possible! Leitax of Barcelona, Spain, is specialized to produce customizing kits for Leica R-mount lenses to make them usable on autofocus DSLRs of the big brands Pentax, Nikon, Sigma, Canon and Sony. Therefore they deliver the necessary replacement mounts as kit with screws and spare bearing ball. If anybody feels uncomfortable making the change he/she can send a customizable lens to Leitax for customizing.