The drum support roller kit (Dryer Repair Kit) allows the dryer to tumble properly by supporting the drum cylinder. The idler pulley provides the tension required for a multi-ribbed belt. The belt attaches to the drum, idler pulley, and motor pulley. If your dryer is damaged, it may be making loud, squeaking, and/or squealing noises while the drum is turning. This is from normal wear and tear. The drum may eventually stop turning all together. This is a sign the part should be replaced. This is one complete maintenance kit. The kit includes the drum belt, drum support rollers, one idler pulley, four tri-rings, and one clip. The parts are constructed of plastic, metal, and rubber, and come in black/white/silver.