The new advanced referee intercom using mesh technology.Good signal,strong penetration,no more disconnection due to referees running free movement on the field or disconnection after referee leave.

Support simultaneous connection of 6 devices of the same model to enjoy unlimited gourp calls

Within the effective distance,you can freely form a group,and after disconnection,you can automatically connect with any user in the front and back of the group,after leaving,the internal automatically connect into group,after coming,you can join  and come automatically connect at any location

covering a dameter of 400-800 meters