The Byron BY102 is a portable 60m chime with 4 sounds & over a million self learning codes. The BY102 will keep the code even when the chime unit is unplugged & then replugged in.
Can have up to 2 bell pushes controlling the chime Eg. Front / back door scenario.
80-90db rating depending on the sound.
Push requires 1 x CR2032 battery (included).