This water pump kit comes with a half moon impeller key and replaces OE#: 0389133 and fits Evinrude Johnson outboard lower units with the following applications: 50 HP 2 Stroke (1971-1978) Please verify the type of impeller key used before purchasing. Some motors use this style and some motors use a plastic wedge impeller key. It is best to confirm the Original Equipment Manufacturers part number matches this listing.