Norton clutch sprocket (chain wheel) friction inserts, 5mm, cork (sold per dozen), UK. Suits Norton clutches from 1933 to 1962. AJS matchless 1957 to 1962. Originals were Ferodo material. Cork inserts work quite well for normal operation. Not recommended for high performance twins eg 650SS. Original part number: 3854 ; A2/394 - Clutch plate inserts