CRF250L '13 - '25 CRF250L Rally '17 - '25 CRF450L '19 - '25 This gasket seals the joint between the head pipe and Exhaust port. These gaskets are designed to crush a little bit to tightly seal where the pipe fits to the head. Get a fresh one now avoid having an exhaust leak when you install your new exhaust. Ships same business day $5.95