prv
Well-Known Member
+1
This is what my engine came with as a secondary filter - same size and shape as an oil filter, just (presumably) a different medium inside. They're not expensive, and they're easy to change. My primary filters (quick-change pair) are Racors where a clear bowl screws onto the bottom of the cartridge and then the whole lot screws onto the head. Very easy to use and reputed to be effective, but the filters are expensive which discourages keeping too many spares. If I was starting again I might well go with screw-on oil-filter style instead.
Pete