Roller bearings 1/4 x 15/64 inch, each. Suit BSA model A7 A10 rigid/ plunger 6 spring clutch and C10L C11G C12 3 spring clutch; suit Triumph twins 1938-1985; BSA A50-A65; suit AJS, Matchless pre 1951 pre Burman B52 gearbox. CP clutch; Suit Burman clutch pre B52 and Triumph clutch all twins 1938 - 1985; BSA A50/A65; PantherOEM numbers57-0394; 570394 - Triumph42-3206 ; 423206- BSA A50/A6535-X - Burman, AJS, MatchlessM734 - PantherT527