The Byron Smartwares BY202 Wireless Plug-In Door Chime Kit has a 100m range, and a chime with 6 sounds. Over a million self-learning codes. Will keep the code even when the chime unit is unplugged and then re-plugged in. Can have up to 6 bell pushes controlling the chime. 80-85dB rating depending on the sound.
F version also has a flashing light alert for the hard of hearing.
The push requires 1 x CR2032 battery (included).