The Sachs Suspension Strut Bellows - 900017 is a protective covering designed to fit over the suspension strut of a vehicle. It is made of durable rubber material and is used to prevent debris, dirt, and moisture from entering the strut assembly. This helps to prolong the life of the suspension components and maintain optimal performance. The bellows also help to reduce noise and vibrations from the suspension system. It is specifically designed to fit the 900017 model of Sachs suspension struts.