Williams AV DWS TGS 23 400 RCH Digi-Wave Tour Guide SystemThe Williams AV DWS TGS 23 400 RCH Digi Wave Tour Guide System is for one guide and up to 23 listeners. The transceiver in the system is DLT 400 from the Digi Wave system. It is a digital spread spectrum (DSS), simultaneous two way wireless listening system. Using a frequency hopping algorithm, it avoids interference and is a very secure method of communication. The Digi Wave communication system allows users to listen and talk to one another