The Sierra 18-7721 Marine Fuel Filter is a high-quality replacement part designed specifically for Mercury outboard engines. It fits the Mercruiser P/N 35-864572, 35-864572T, and 35-864572T01 as well as the Mallory P/N 9-37826. This fuel filter is manufactured by Sierra, a trusted brand in marine parts. With this filter, boat owners can ensure their engines are getting the clean fuel they need for optimal performance.