 Some models are flash synchronized, using Canon's side-rail synch contacts.The lens mount is compatible with all standard Leitz M39 mount lenses

The original ones came with a spring-loaded takeup spool that most photographers found easier to use than the one provided by Leica—many are now missing the spool since the spools were taken for use in Leica cameras.Unlike many Leica copies, quality control and finish are fully up to Leitz standards.