EJEAS V6C Referee Bluetooth Intercom, 850mAh Full Duplex 1200M Wireless Bluetooth Interphone with Referees Headset and Running Arm Band for Football Hockey Rugby Sport, USB-C (2-Pack)Professional Referee Intercom: Equipped with Bluetooth 5. 1 chip, Bluetooth helmet intercom can be paired with up to 6 people and provides real time intercom for 2 people within an effective range of up to 1000 meters (barrier free). In particular, 2 packs of V6C can be connected to 1 package V4C, creating a 3 way communication system that gives 3 referees the ability to communicate simultaneously Noise Cancelling Technology The V6C referee