Tapered roller bearings consist of four interdependent components: the cone, or inner ring, the cup, or outer ring, the tapered rollers, or rolling elements and the cage, or roller retainer. The taper angles allow the bearing to handle a combination of radial and thrust loads. The steeper the cup angle, the greater the ability of the bearing to handle thrust loads. Tapered roller bearings are a unique subset of axial roller bearings in which the rollers are tapered rather than straight right cylindrical. The roller shape allows thrust loads to be withstood in addition to the radial loads. A familiar application for tapered roller bearings is the central hub bearings for automobile wheels. Tapered roller bearings use conical rollers that run on conical races. Most roller bearings only take radial loads, but taper roller bearings support both radial and axial loads, and generally can carry higher loads than ball bearings due to greater contact area.