91503-ZY1-300 Collar (6.5X11X10) - Overview. The 91503-ZY1-300 Collar (6.5X11X10) is a genuine Honda marine engine system component designed to support rigging and accessory assembly. It functions as a precise collar with dimensions of 6.5mm x 11mm x 10mm, playing a critical role in stabilizing and aligning parts within the marine engine ecosystem. Engineered to exact factory specifications, the collar ensures seamless integration with existing parts, maintaining optimal performance and durabili