Overview: With the Features of BT 4.2 technology, 3.5mm Audio Port, built-in Microphone and Speaker, TF Card MP3 Player, Hands-free call, and FM Radio, the BT Headphone is a super companion for you during daily life and travel. Features: Multifunctional: Equipped with Features of BT connection, TF card music playing, AUX-IN wired music playing, FM radio, and hands-free call with Microphone. BT Connection: With BT4.2 function, easy to pair with almost all the BT-enabled audio devices, freely to enjoy wireless music and hands-free calls. AUX-IN Function: Connect to the audio devices (such as MP3/MP4, Laptop, etc) without BT function via the 3.5mm audio cable (NOT included). Long Battery Life: Built-in 250mAh rechargeable battery lasts up to 10 hours of music playing time per charge cycle. Ergonomic Design: Adjustable headband length, foldable soft leather ear cushion, comfortable to wear, and easy for storage. High-sensitive Mic: HD microphone reduces ambient noises and grasps the detail of voice. You can get high-quality hands-free phone conversation. Specifications: Brand Name: NIA Model Number: S4000 BT Version: 4.2 Support Profiles: A2DP/ACRCP Operation Range: 10 meters (no obstacle) Frequency Response: 20Hz-20KHz Impedance: 32 Sensitivity: 1083dB FM Frequency: 87.5-108MHz Music Format: MP3, WMA, WAV Speaker Unit: 40mm Battery Capacity: 250mAh (depends on music volume) Working Time: about 10 hours Standby Time: about 200 hours Charging Time: about 2 hours Charging Port: Micro USB Color: Black Item Size: approx. 19.6*17.3*8.2cm/7.71*6.81*3.22in Item Weight: 222g/7.83oz Package Size: 18.8*18.5*9.5cm/7.40*7.28*3.74in Package Weight: 363g/12.80in Packing List: 1 * NIA S4000 Headset 1 * Charging Cable 1 * User Manual (English)