Dual use bearing fits the end of the A Plus 18mm mainshaft where the Ist Motion shaft slides on, plus it is used on the A Plus layshaft smaller end.
Knowm as the 18mm bearing it was Rovers upgrade on using larger mainshafts and laygears with 3 step layshaft.
CHM141 still fits the larger end of 4 Synchro layshafts.
Original bearing had 14 rollers but new stock has only 11.