Nank runner 4 bone conduction headphone-The perfect niche product

Bone conduction headphones are becoming more and more popular, for anyone who want to do exercise, while also want to hear music at the same time, it is a good choice. I purchased a Nank runner 4 recently.
The good:
?Not only for running, but also perfect for swimming, which has a  IP68 waterproof function.
?Extremely light. You put them on your head and you forget about them
?Secure for sports lover; You can hear everything around you 100%
?Controls are easy, turn power on and that's it.
?Enough storage to store the mp3 files
?Easy language switch control
The bad:
?Not enough colors available
? Should not be used in salt water.