Specifications：

5 people to enter the referee at the same time Bluetooth + Bluetooth Headset
Under ideal conditions the maximum call between two users distance of up to 1200 meters, truly in full duplex wireless communication between Bluetooth system of four riders
Automatic safety receives phone calls
Strong shake stereo music / audio function (with A2DP mobile phone transmission / MP3 / GPS)
DSP noise cancellation
Built-in lithium polymer battery capacity 500 mA
National 5 waterproof standard
FM tuner
5 people can talk at the same time

Feature:

Bluetooth Version: 3.0, Advanced A2DP & EDR Bluetooth
Chip: CSR BC5
Operating voltage: 3.3V-4.2V
Talk time: 8 hours, standby time: 120 hours, charging time: 2.5 hours
Radio frequency: 76M-108MHZ
Speaker power: 0.25W
Have automatic volume adjustment: Yes
Operating temperature range: -10 ℃ to + 45 ℃

Package includes:

1 * interphone
1 * USB charging cable
1 * earphone
1 * deck
1 * Power Adapter
1 * Manual
1 * armband