The Wireless Full Duplex Headsets Add-On to Telex Wired Intercom (Two UltraLITE Single) from Eartec utilizes Eartec's HUB Interface to create a wireless communications system that connects to your wired Telex intercom system. Simple to setup, you can expand your hardwired intercom system by up to eight users that can communicate in full duplex without being physically tethered to the intercom. Push-button adjustments balance the signal levels between the wired system and the HUB, creating a seamless audio link. This setup includes two headsets, allowing you to add up to six more UltraLITE headsets as your needs increase.