Ultralite UL4S KIT HD

Designed to facilitate wireless coordination and communication, the UL4S UltraLITE from Eartec is a 4-person single-eared headset system suitable for use on film sets, theater sets, and more. Each headset weighs only 4 oz, can receive audio at a speed of 1.152 Mbps, and can last six hours before requiring a recharge, which you can accomplish via the included charging station. Its microphone can swivel 270°. When you're done, simply pack it all up in the case. These headsets will receive audio at ranges of over 1000'.
Type 4 x single-eared

Single-ear Ultralite headphones 4 units kit
System doesn't need a Ultralite hub to work(up to 4 units)
Complete with carring case and Includes 8-Port Charging Station

Be aware that :
- for many headphones , If you use HUB you can't have more than one Master slave, but one master only which can work with up to 6 slave and one connected with HUB.
- If you have a Master headphone ( no hub ) up to 3 slave.
- in no case is possible to have in the same partyline more than one master.