Specifications: Bluetooth Version: Bluetooth v2.1 +EDR Working Range: Up to 10m Built-in 500mAh Rechargeable Battery Working Time: 3-5 hours Support A2DP V1.2, AVRCP V1.4 profiles Support Line-In, Handsfree call, Micro SD Card Playing Distortion: 0.5% Fregqency Reponse: 100HZ - 18KHZ With LED Indicating when Working Unique Design with great sound quality