Konftel BT30 works fine with Konftel Ego and Konftel 55Wx* but with limited Bluetooth range. 

To get the full Bluetooth Class 1 range you need to pair Konftel BT30 with Konftel 70 or Konftel 800.

* you need to activate "Bluetooth voice compatibility mode" on Konftel 55Wx. 

You can do this by holding "System" menu button in settings for 4 seconds.