The #608 is the small bearing on most 21 size engines like the K21, CMB21, A/A21 and the MAC 21.
Dimension: 8mm X 22mm X 7mm( .3149” X .8661” X .2775”) ...
AA .21 "O" Ring Set. Give your engine a refresh and replace your "O" Ring Set before the start of the new boating season to avoid unnecessary failure. ...