12373-ZV1-000 Breather Cap Gasket - Overview. The 12373-ZV1-000 Breather Cap Gasket is a vital sealing component for Honda marine engine systems. Its primary role is to create a secure seal on the breather cap, preventing dirt and moisture ingress while allowing the engine to ventilate correctly. Designed to meet factory specifications, this gasket ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Gasket designed to seal the breather