Not "compatible"

Though this add-on handset is advertised as working with a wide variety of Uniden base stations, it only fits the charger base of the latest 900 series phones. We bought it to expand a system based on the TRU8865, and now have to keep track of what model number will charge in what charger - eliminating the main convenience of the system.

Worse still, when contacting customer support we were told - rudely and repeatedly - that they had promised only "compatibility, not "interchangeability." I guess we need to consult a dictionary before ordering phones.