One of the innovative features of the rack-mountable Datavideo ITC-100 8-User Wired Intercom System with 4 Beltbacks & 4 Headsets is that it can use headsets ranging from low-cost cell phone headsets to high-quality professional units. Up to 8 users can be connected to the ITC-100 via PTT wired beltpacks. Four beltpacks, four headsets, four cables and a tally light set are all included. Cables for connecting the beltpacks may be up to 984 ft long, and use 5-pin XLR connectors. The base station features all call and mute buttons, a mic input, built-in speaker, and standard headphone jacks.