Music is a super companion for humans, which can make you relaxing and enjoy colorful life. A portable music player device is essential for music lover. We are be honored to recommend K2 Stereo Bluetooth Headphones to you. K2 Bluetooth Headphone is specially designed for music lovers and sports enthusiast, which features Advanced True Wireless Bluetooth 4.1 (CSR4.1) Technology, Built-in high-grade Microphone & Speaker, hands-free function and lightweight design. It will offer you wonderful music, you can greatly enjoy your favorite Music. A super companion for you during daily life and travel.    

Features:
[Advanced Bluetooth Technology]
Latest True Wireless BT 4.1 (CSR4.1) Technology with A2DP/ AVRCP support, ensure transmitting strong signal in high quality & high speed and offering high-fidelity stereo music. Offering Strong Wireless Signal, with a wireless audio range of 33ft (10m), enjoy the freedom to move and the convenience of uncompromising sound quality. 
[Unique Design]
Wireless Dual Ear Stereo Design, Left and Right Ear Channel Separation; You can use K2's Left and Right Ear Headset solely (Single Track Mode), and K2 also can be used in pairs (Stereo Mode). Ultra Mini Size(its diameter is only 20mm), offering you Wonderful High fidelity Stereo Sound Effect. Its ergonomic design guarantees 100% Stable and Comfortable when walking, exercising, running, climbing, driving, skating, cycling, fishing and other outdoor sports. 
[Emergency Power Supply] 
Comes with 450mAh Emergency Power Bank Box, which can be used as a portable power bank and offering Emergency Power Supply to the Bluetooth Headphone (Supports charging the Bluetooth Headphone more than 4 Times) when in urgent need, keeping you enjoying wonderful music all day without any worry for low battery. 
[CVC6.0 Noise Cancellation & High-sensitivity Mic]
Adopt Built-in CVC6.0 Noise Canceling Technology and high-sensitivity microphone to reduces ambient noises and grasp the detail of voice, enabling clearer sound from microphone. You can get high quality hands-free phone conversation even on the street or inside a shopping mall. 
[Long Standby Time & Fully Compatibility]
Built-in rechargeable Lithium battery lasts up to 4 hours of Talking Time / 3 hours of Music Playing Time and 40 hours of Standby Time per charge cycle. And universally compatible with most Bluetooth-enabled devices, including iOS / Android / Windows Smart phones & Tablet PC and other Bluetooth devices. 

Specifications:
Product Type: True Wireless BT Stereo Headphone.
Bluetooth Version: Bluetooth 4.1 (CSR)+ EDR; Class 2.
Supports HSP, HFP, A2DP, AVRCP protocol. 
Battery Capacity Display, supports for iPhone. 
Frequency Response Range: 21Hz-18KHZ
Operation Range: Up to 10 meters 
Microphone: Built-in high-sensitivity microphone (-38dB).
Impedance: 16Ω 
Sensitivity: 95dB
Degree of distortion: ≤1%
SNR ≥95
Headset Battery: 60mAh Rechargeable Li-ion battery
Power Bank Box Battery: 450mAh Rechargeable Li-ion battery
Charge Time (for Power Bank Box): About 2.0 hours 
Music Playing Time: About 3 hours (The Music Volume will affect the time)
Talk Time: About 4 hours
Standby Time: 40 hours
Charge Time:1 ~ 2 hours
Charge Port: Micro USB
Color: Black
Main Item Size: 2.8 * 2.8 * 2.0cm / 1.1 * 1.1 * 0.79in
Main Item Weight: 10g / 0.37oz
Package size: 18.0 * 9.0 * 3.5cm / 7.0 * 3.54 * 1.37 in
Package weight: 112g / 3.97oz

Package List:
1 * K2 True Wireless Bluetooth Headset    
1 * USB Cable
3 * Earbud
1 * English / Chinese User Manual