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: 32Ω
Sensitivity: 108±3dB
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