The Mercury-Mercruiser 35-8M0123025 Oil Filter keeps oil cleaner longer with the unique filtration system that screens particles smaller than 1/1000th of an inch, The high efficiency design allows for oil to flow at a constant rate to the engine vital points. Thanks to a metal shell that is over 50% thicker than conventional filters, this filter is built to last. Provides maximum protection for the 175-450 HP V6 and V8 FourStroke Outboards. For normal use the fuel filter should be changed every 100 hours or at least after every season.