Byron BY103 Wirefree Plug Through Chime Kit 60m BYRBY103 The Byron BY103 is a 4 melody 60m plug-through chime kit. Simply plug in to any household 3-pin socket and the unit is ready to use. With the Byron BY103 you will not lose the socket as any appliance can be plugged in to the door chime and still operate. No loss of socket. Self learning. Push requires 1 x CR2032 battery (included). BYRBY103