Check out any of the twenty-one Rear Cushion Lever (model J) components enlisted.
The most reasonably priced component used on the Gsx600f Katana 1990 (l) Usa (e03) Rear Cushion Lever (model J) is the Nut 12mm.
A sample from the products for the Rear Cushion Lever (model J) include: Bearing(20x27x30), Rod Set,rr Cushion,r, Nut 14mm, Bearing(17x24x26).