This is known as a tub bearing or a rear bearing, and it is part for your washing machine. The function of this bearing is to be a support for the spin basket shaft that is located at the back of the washer tub. This model is sold individually and measures to have a 2.5-inch outer diameter. As this bearing is very difficult to install, the manufacturer recommends completely replacing the rear tub and bearing assembly. If you are only installing the rear bearing, consider replacing the seal and the other bearing as they wear out together.