Designed to protect the oil pump and cam plate from debris off the chain-tensioners or other particles that may come loose in a Twin Cam engine Great to put in when doing a cam bearing job Keeps cam bearing rollers from dropping into the center section of your engine, which could ruin the oil pump and cam plate Does not restrict oil flow - in testing the engine returned the same amount of oil back to the oil tank in an allotted amount of time; the screens de-aerate the oil more, which drops oil temperature 5-10?F Easy-to-install and clean Made in the U.S.A.. SCREENS OIL PUMP 99-17TC