The Bolt,6x16 is the cheapest item from this partsfiche.
A sample from the products for the Breather Cover/oil Pan include: Ring-o,91.6x3.4, Gasket,drain Plug Bol (nas), Bolt,6x16, Bolt-upset 6x14.
The Kawasaki BREATHER COVER/OIL PAN has twenty-two products enlisted in the schematic.