The Williams AV DWS INT 3 400 ALK Digi-Wave Interpretation System is for two presenters and up to 20 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 wirelessly in a variety of scenarios. The receiver uses alkaline batteries.

A headset microphone and earphones are for use by the speaker and listeners. Headset microphone MIC 144 has a TRRS 3.5 mm plug and is for use with Digi-Wave DLT 400 transceiver only. The earphone hangs on the outside of the ear, excellent for use from one person to the next. This earphone is specifically designed for listeners with mild and low gain hearing loss.