40105-ZZ5-000 Case (Lower) Grom - Overview. The 40105-ZZ5-000 Case (Lower) Grom is an essential rubber grommet used in Honda marine engine systems. It is designed to support the lower case assembly system, primarily serving as a protective seal that prevents water intrusion and secures rigging hoses or cables. This part is vital for maintaining the reliability and efficiency of the engine's lower case, ensuring seamless integration with existing parts, maintaining optimal performance and durabil