hi the kanuni 301 rear srocket is a bolt on the hub design 48 teeth the mz 301 rear sprocket is cast on to the rear hub so only replaceable as a compleate unit used mzparcalari in turkey for replacement of rear sprocket for my kanuni at $25 plus shipping good price quality good delivery times well some times 8 days other times 3 weeks ? if you want the part and its not available in uk take a chance usually arrives, see threads on this site, front sprockets normally 22 teeth can change what style of riding do you want see mz shop phil speakman or mz parts burwins of london hope this helps