Feature: Bluetooth stereo headphone, offers you quality streaming music enjoy When connects with phone, hands free to make calling or answer calling Up to 10 hours music playback, 200 hours standby 33feet/10 meters working range lightweight neckband foldable design Built-in Microphone offers you convinience to answer or make cell phone calls Foldable compact design provides maximum comfort and protability perience. Furthermore, it's convenient and easy to take with you wherever you go. Compatibility:Bluetooth-enabled devices, like a Smartphone, tablet, MP3 player Specifications: Bluetooth Spec: V2.1+EDR Class II Bluetooth Profile: Headse, Handsfree,A2DP, AVRCP Frequency:2400-2483.5MHZ Speaker Diameter: 30MM Talk Time: 9 Hours Standby Time: UP to 250 Hours Charging Time: 2~3 Hours Audio Out Power: 17mW Sensitivity: <-42dB Dimensions: 2.5in x 2.5in x 1.5in (Coiled) Up to 33 feet(10 meters) working range Maximun power dissipation:25Mah +/-5 Working Voltage: 3.0-4.2V Package include: 1 x mini 503 bluetooth headset 1 x User Manual 1 x usb cable