Features:Bluetooth3.0 HSP， HFP， A2DP， AVRC profiles supportedCalls handling500M full duplex intercom4 buttons operationAux audio inputFirmware USB upgrade availableCalls， music volume up/down independent and adjustableFull weather protected， better waterproof performanceIt can pair "rider to rider" or "rider to pillion". Can pair 11 Intercoms at a time， and easily switch to any 2 of themWorks with any Bluetooth equipped mobile phone，GPS or MP3 Stereo music CD player/iPod and etc. by connecting the headphone wires directly (without main unit)Plastic + Rubber button， more stable structure， better waterproof performance.Wireless hands free communication for motorcyclist Safe driving while talking with friends Can be used as a Bluetooth headset and a wireless music headset while you're not ridingSpecifications:1). Bluetooth Version: Bluetooth 3.02). Chip: CSR BlueCore5MM 3). Model: DK_218M4). Intercom transmission distance: 500M5). Mobile Phone Connection transmitting range:10M5). RF Frequency: 2.4GHZ6). Bluetooth RF Spec: Class 17). RF Power:16dB8). Standby Time:100 Hours9). Cell Phone Talk Time: 8Hours10). Intercom Talk Time:8Hours11). Music Play Time: 8Hours12). Charge Time:3Hours13). Battery: DC5.0V/500mA14). Battery Type:Li-polymer Battery 500mAh15). Working Voltage:3.3--4.2V16). Color: Black17). Applicable model: Compatible with all major brands of Bluetooth mobile phone and Bluetooth GPSPackage Included:1 X Host1 X USB Charging cable1 X D2 Retaining clip1 X Hexagonal screwdriver1 X Headset Speakers1 X User Manual