3pcs V6 V4 Full Duplex Two-way Football Referee Coach Judger Arbitro football referee headset(Only earphone,You need to buy the intercom body if you don"'"t have them)Now we have 2 models, we will send model 1 as default, if you need model 2, please leave messageWhat can you do with thisFootball Referee Coach Judger Arbitro football referee headset ?The Bluetooth device is designed for the referee, aerial photography, mountaineering, ski enthusiasts a multifunction device, which can be used for the following purposes:1) can be used as a hands-phone call device Bluetooth headsetWhen law enforcement football game referee, outdoor aerial, cranes, climbing, skiing, skateboarding, hiking, ALICE team, motorcycle travel team when you are safe to use internal Bluetooth function calls. - When the phone is turned on, you do not need to press any buttons, you can ride as usual, about five seconds later, the phone will automatically turn; of course it also has refused to answer the phone function.2) between two, three, four users bidirectional full-duplex wireless intercom (with a few people on the use of several paired)The maximum communication distance at a high clear line of sight path can reach the ideal state of vacuum 1200m, usually in open unobstructed environment effective distance of about 600m or so. Please note that the actual range will ultimately depend on weather conditions, terrain, presence obstacles, namely large vehicles or invisible buildingsReal full-time one-way intercom can be concerned, because it is half-duplex, a person can only say that a person to listen, speak and can not achieve the dual function of listening, and our V4C like a regular phone as workers conversation.3) For calls MP3 / GPSIf your MP3 or GPS is not Bluetooth features and you also do not have a Bluetooth AV dongle, this Bluetooth device also provides another simple way to listen to music in stereo wired / audio information. It is directly connected through the 3.5 mm audio jack and Bluetooth device. In order to achieve the function of listening to stereo musicPackage:3x Football Referee Coach Judger Arbitro football referee headset