90602-ZW5-030 Tube (D12) Clamp - Overview. The 90602-ZW5-030 Tube (D12) Clamp is a vital component within Honda marine engine systems. This clamp is engineered to secure D12 diameter tubing, playing a crucial role in maintaining the integrity and operational reliability of the marine engine's rigging and accessory systems. By securely anchoring the tubing, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Designed specifically as