87121-ZV1-C01 Rr Mark - Overview. The 87121-ZV1-C01 RR MARK is a genuine OEM part designed for precise integration with Honda marine engine systems. This rear mark component plays a subtle but essential role in ensuring the proper identification and alignment of engine parts within the marine propulsion system. Engineered to meet strict factory specifications and tolerances, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Specif