SMALLER BUT LOUDER. Main Features: - Bluetooth 3.0 technology for lower energy consumption but more stable connection and faster transmits speed, wireless operating distance is up to 10m ( barrier-free space ) - Bluetooth wireless design for connecting to any Bluetooth enabled smart devices - Very easy to set up and use, your Bluetooth is ready, your music is ready - Can play music from AUX, and TF card directly, very convenient to use - Bluetooth wireless design for connecting to any Bluetooth enabled smart devices - Built-in 2500mAh rechargeable li-ion battery supplies 4 - 8hours music time - Two slip resistant rubber outsoles create a safe music playing environment - Built-in noise cancellation function microphone, you can have a more clear and safer call with your families and friends Specifications: Bluetooth Version: V3.0 + EDR Battery: Built-in 2500mAh rechargable battery Charging Time: 1.5 - 2hours Frequency Response:100Hz - 18KHz Support Format: WAV, MP3, WMA, APE, FLC Output Power: 4.5W x 2 S/N: 82dB SPL Rated Impedance: 4Ohm Speaker Unit: 40mm double speaker 16 core Input Sensitivity: 500mA SNR: No less than 80dBA Distortion: Less than 1 percent Operating Voltage: 3.7V Channels: 1 Model Number: Y - 200 Special Feature: Portable,Wireless Type: Active Package weight: 0.662 kg Product Size(L x W x H): 14.00 x 8.50 x 6.00 cm / 5.51 x 3.35 x 2.36 inches Package Size(L x W x H): 21.50 x 11.30 x 8.20 cm / 8.46 x 4.45 x 3.23 inches. It has no warranty.