91555-ZY9-000 P.t.t Relay Collar - Overview. The 91555-ZY9-000 P.T.T Relay Collar is an essential component in Honda marine engine systems. It plays a critical role within the power tilt and trim (P.T.T) system, serving as a collar or housing part for the relay that controls the motor's tilt and trim function. By ensuring smooth operation of the P.T.T system, it helps maintain the reliability and performance of your marine equipment. Designed for Honda engines, it guarantees seamless integration