Water Separating Fuel Filter – a spin on fuel filter that is suitable for most inboard and outboard petrol engines. Features: 25 micron filter separates water from fuel and removes imputities, filter features a metal shell that is over 50% thicker than conventional filters, Durable paint finish to resist corrosion - even in saltwater environments, Epoxy coated internal surfaces that resist rust caused by water captured within filter. Application: Fits all Mercury, Mariner and Force outboards equipped with externally mounted water separating fuel filter bases, Fits all Mercury MerCruiser applications except 1992 4.3L Generation II engines with an in-line fuel filter, Also fits Yamaha,Suzuki SMI, Volvo Penta and other filter heads. Change the fuel filter every 100 engine hours or min. once in season.