Husqvarna 578398201  Bushing, 20/25 4mm Dia

The Bushing, sometimes called a sleeve bushing or flange bushing, is a cylindrical shaped rubber or plastic part often used to limit the size of an opening, decrease abrasion, or serve as a guide or lining for a hole. Depending on the type of equipment, preventative maintenance suggestions often include installing fresh bushings. Unlike some bearings that can be cleaned or greased, most bushings must simply be replaced if they become brittle or crack.