Earfree foldable neckband bone conduction blue tooth earphones open ear wireless bone conduction sport headphones

1 Compatible with almost all Bluetooth-enabled mobile devices such as, for mobile phones ,smartphones,Table PC ,etc. 
2 Conducts sound through users' temporal bone

3 Super easy and fast connecting with your smartphone or other Bluetooth device for high-fidelity stereo music, movies and chatting.
4 No eardrum damage, it is an healthy, eco-friendly headphone, suitable for child, young people, and also suitable for the person who uses the headphone frequently to avoid damaging the ear.  
5 The sound transmits through the bone to auditory nerve, perfectly suitable for people has trouble in listen and suitable any other people. 
6 With Bluetooth 4.0 + EDR chip, it ensures high-fidelity stereo sound quality and stable performance.
Low consumption, offering up to 6 hours of continuous music and 5 hours of talking time. Standby time is about 240 hours.
7  It supports hands-free call.
8  Enjoy music wirelessly, easy to switch between calls and music, you will not miss any incoming call while listening to music.
9  Its Sweatproof U-shaped ergonomical design is suitable for walking, running, climbing, skating, skiing sport, diving, etc.

10 Provides the perfect, comfortable fit to the back of your head

Specifications:

-Bluetooth version: V 4.0
-Bluetooth power: Class II
-Li battery: 3.7V/200mAh
-Standy time: 30 days
-Charging tiem: around 3 hours
-Bluetooth frequency: 2402HZ~2480Hz
-Transission range: 10 meters
-Vibrator diameter: Φ15m
-Vibrator ipedance: 8Ω
-Frequency response: 50~20KHz
-Microphone size: 4.0*1.5mm
-Microphone sensitive: -52dB+3dB
-Microphone direction: Omni directional
-Microphone response: 100Hz~8KHz
-USB-USB micro cable lenght: 80cm