The Byron Smartware B322 Portable Wireless Plug-In Door Chime Kit has a 50 metre operating distance. It features self-learning codes and will keep the code even when the batteries run out and are replaced. It comes with a portable chime, that can be placed in a different room to the plug in chime. It has a 80-85dB rating, depending on the sound. Compatible with all Byron DB ranges.
The plug-in chime is mains powered.
The push requires 1 x 23A battery (included).
The portable chime requires 3 x AA batteries (NOT included).