40201-ZV7-020ZB Case *NHB14M* - Overview. The 40201-ZV7-020ZB Case *NHB14M* is an essential component designed specifically for Honda marine engine systems. This extension case serves as a protective housing that supports the driveshaft and related mechanical elements crucial to the reliable operation of your marine engine. Engineered to meet factory specifications, it ensures seamless integration with existing parts, maintaining optimal performance and durability.. Key Features. Extension case