I will add, that ebay item above is nice that it unscrews so you can clean it, its glass so you can see the crud, but mine was on a car with known slight rust issues in the tank. I would clean it about 3 times a year, but about once a year it would run poorly, and when I looked in the carb bowl it would have very fine mud in the bottom. This was on a model A, easy job to pull the carb and blow it out once a year or so, but the filter was not fine enough to get the small stuff that eventually will cause a problem if you have a mild rust issue like me. this car gets driven...alot, not rust from non-use