The Eartec UltraLITE is a breakthrough full duplex wireless headset that provides hands-free, two-way voice communications. At the heart of these systems is a specialty "Master" headset that relays the digital signals generated by up to three "Remote" units. The resulting open line talking pattern allows up to 4 people to talk simultaneously without pushing buttons. To formulate your standard UltraLITE system, select any combination of Double or Single ear headsets, up to 4 units.