This is also called the "1st motion bearing" and holds the centre of the first motion shaft in place. It is a highly loaded component, so should be replaced if in doubt!
Suits ALL gearboxes that DO NOT have first gear synchro. Part number is 21MJ1 made by RHP UK and is the genuine article.
Some suppliers are providing a Japanese metric bearing that is too small in outside diameter and we believe it does not suit. This is now an NLA product, although we have very limited stock.