A device can include a housing that comprises a front side that includes a display operatively coupled to display circuitry and a back side that comprises a ferromagnetic surface, a hinge assembly, and a recess; and a ferromagnetic panel transitionable via the hinge assembly from a storage position in the recess to a bridge position that covers the ferromagnetic surface.

A first seal and a second seal seal an annular space between an outer ring and an inner ring by sandwiching a retainer. A stator including a coil is supported by the first seal and is opposed to a magnetic ring. A sensor, a wireless communication circuit, and a power supply circuit are supported by the second seal. A wire electrically connects the coil and the power supply circuit. The wire includes a part disposed in a groove extending in an axial direction of a bearing on an outer peripheral surface of the outer ring.