Feature: 1. Bluetooth + MP3 function support stereo music playing, phone calling. 2. Support all audio devices that have Bluetooth capability, such as, cell phone ,tablet PC,laptop,computer etc. 3. 3.5mm audio jack, provides a simple wired connection of a variety of devices without Bluetooth. 4. Allow you to answer or reject phone calls anytime and anywhere. 5. Charged via USB, rechargeable battery, convenient and practical. 6. Playing time up to 10 hours, and continue talk time up to 8 hours, standby time up to 250 hours. 7. Good quality, foldable design and adjustable length hinges, very comfortable to wear and easy to carry. 8. Best choice for listening music, watching movie, chatting online etc. 9. with SD card insert,without any bluetooth device,can still enjoy music any time any where. 10.Cool shinning outlook adds the fashionable feel. Version:V5.0 Frequency:2.40GHz-2.48GHz Power: 4 dBm, class 2 Effective range:10M Sensitivity:-84dBm / 0.1% BER Frequency response:20 Hz - 20 KHz S/N rate:70 dB Distortion:0.10% Speaker size:40mm support:A2DP 1.2, AVRCP 1.0, HSP, HSF 1.5 Voltage:3.7VDC (built-in 400MAH rechargeable battery) talking time:20 hour standby time:360hour charge time:2-2.5 hour current:40 mA operate temperature:-4 ~ +131F(-20 ~ +55C)