Thanks to the 30 freely programmable keys, including LED support, which can be assigned in two levels like the Sensorfon ST 56 (IP), the STE 56 makes it easier for anyone who needs to manage a variety of phone numbers and functions. This way, you can see at a glance which colleagues are currently speaking and can perfectly coordinate incoming calls. The STE 56 can only be operated in conjunction with the Agfeo system phones ST 56 and ST 56 IP. A maximum of three STE 56 units can be connected to one system phone. The total number of connectable STE 56 units depends on the communication system being used.