Use when engine has a bigger housing (SAE 1) than the transmission and needs adapter. Also buy gasket below (SAE 2 - smaller) for adaptor to transmission
For Allsion Marine Transmission MH15,MH15L,MH15R,MH20,MH20L,MH20R,MH30,MH30L,MH30R,MH45,MH45L,MH45R,MH50