With two applications this O-ring,3.7x1.5 is the most specified part.
A sample from the products for the Gasket Kit B include: Gskt.r Cover (mca), O Ring 17.0x2.5, Gasket,l Cover (nas), O Ring,26mm.
This Gasket Kit B diagram displays the required parts for the Cmx450c Rebel 1986 (g) Usa California Gasket Kit B.