The Twin Cam oil pump screens were 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. They are great to put in when doing a cam bearing job. The screens are easy to install and to clean. When the screens plug, the oil will not scavenge out of the engine. Oil will eventually come out of the air cleaner. This is telling you that something is coming apart in the engine and it is time to service the cam area. Screens do not cause restriction. It was determined that the screens de-aerated the oil more. Thus, about a 5 to 10 degree oil temperature drop occurs. Fits all Twin Cam engines 1999-2017.