The Panasonic KX-HDV20 expansion module is designed for easy connection to Panasonic's HDV230, HDV330 and HDV430 IP desk phones. This keypad offers 20 additional keys with two-page view for up to 40 programmable functions.
A maximum of 5 of these consoles can be connected to one IP desk phone for a total of 100 additional keys / 200 additional programmable functions.
Please note: This solution requires the host phone to be powered via PSU.