Thank you. I have five orings in the soare crossland 522 filter; two large that i assume go on top/bottom of replacement filter.
Three smaller ones; around 12mm, 6mm abd 4mm.
You will all be amused to hear its in a really fun place to get to!!! (Not).
The two large ones will be for either side of your new filter. But there is also one between the glass bowl and the base plate, this should be changed also, you need to buy extra O-rings if you have a glass bowl.
If you take your time and are careful it shouldn't be a problem.
IIRC, the third large O ring is a different size to the other two. As you say, best to replace with a spin on filter, I won't have a CAV 296 on a boat.
The glass (PYREX ovenproof) bowl seal is not included in most generic filters