Byron HE306 Wirefree Door Bell In summary this doorbell connects wirelessly to a plug in chime. The chime plugs into any mains socket and itself has a pass through mains socket. You can plug a device such as a lamp into the mains socket, and when someone presses the doorbell the chime will sound AND the lamp will illuminate, either flash or continuous. ---Totally wireless. ---Range, 40 metres. ---7 selectable timer functions. ---Ideal for Hard of Hearing ---Signal passes through walls and ceilings. ---Important: mounting the bell push unit onto a UPVC door frame or metal surface will reduce the operating range and may cause the units to work intermittently. ---Chime Unit, HE-306R, Indoor use only. ---Bell Push Button, HE-306T, Outdoor Use. ---Bell Push Size, 50mm x 90mm x 24mm ---Frequency 433.92MHz.