A cover for a ring

A protective cover for a smart ring comprising an annular member formed from flexible material adapted to stretch over a ring, the protective cover having a circular shape comprising an inner surface, an outer surface and side walls joining adjacent ends of the inner and outer surfaces, and wherein in use and when fitted to a ring the side walls extend radially inwards along an annular surface of the ring and the inner surface receives the exterior surfaces of the ring, wherein the diameter of the inner surface is smaller than the outer diameter of the ring and the side walls are configured to ensure the contact between internal sensors of the smart ring and the skin of the ring wearer's finger is maintained.