This separates is composed of suction-strainer, Trochoid pump, Pre-filtration element which removes soft agents such as contaminants and depleted agents as well as makes water particles aggregate together, and Water Separation filter inserted in WS housing. The lower part of WS housing is made of clear acrylic resin, so that you can observe the water separation degree at a glance. The drain valve affixed on WS housing is to drain the separated water.