Bone Conduction headphones, Gendax Wireless Bluetooth 4.0 Bone Conduction Earphone Headphones Headset with Built-in Microphone for City Sports like Cycling Riding Driving and Jogging (black) Innovative Bone Conduction Technology -- Transmit sound through the skull directly to the auditory center, which eliminates many steps of acoustic transmission. It can achieve clear sound reduction in a noisy environment, so as to release the ears and revert to the delicate tone function. Suitable for people who jog, run, cycle, etc Built-in Headphone, Free Your Hands: Wireless bone conduction headphone ensures handsfree calling / answering and music listening in driving,riding. Adjustable silicone tension band for tight and comfortable wearing. No worries of the headset falling. Bluetooth4.0 is fully backward compatible with most Bluetooth version device . Such as iPhone6s plus 5S 5 4S and Android smartphones, Samsung Galaxy Phones and so on. Less Interference, More Safety-- Bone conduction speaker makes the sound directly transmitted to bone chain through internal conduction of bone, helps you enjoy the purest sound and keep sensitivity to surrounding sound in a noisy environment.