The byron smartwares by323 wireless portable plug through kit has a 60m range and a chime with 4 sounds the socket can still be used as any appliance can be plugged into the door chime and still operate the plug through feature means that no socket is lost another mains powered object can be powered by plugging into the chime the portable chime requires 3 x aa batteries not included the push requires 1 x cr2032 battery included