See Through Oil Filter Assemblies allow the user to Quickly and Easily check filtered particles in an oil or fluid system. Filter can be emptied without draining or leaking any oil, and without unbolting or loosening any fasteners or fittings! Being able to examine filtered particles within seconds is a benefit to any engine combination, by being able to see any failures in the engine before they become catastrophic. These Filters are like having an Insurance Policy on your engine.