It changed to chinese while I was carrying it in my pocket (I ran into someone, so I threw it in with it still on, possibly still playing). It took me a long time to figure out how to get it back to English.
1. Start with a turned-off unit.
2. Press and hold the big button.
3. After a couple of seconds, it says something, which means “Device on.”
4. Keep holding the button, and immediately after it says something longer, which means “Pairing mode, on.”
5. Release the button and immediately give it a short click and a long click. So [hold for a few seconds till pairing on] [click] [press and hold for 2 seconds]
6. the unit should speak “English mode on.”
In terms of the unit, it works surprisingly well. It is not as secure as the same ear bud design from Plantronics in my small ear, but it lets me jog my dog and not fall off. The sound is slightly scratchy so won’t make a great music experience but not worse than other units of this size. The earbud does not completely seal the ear, so I still have very good awareness of the surroundings while walking on the street. The noise cancelling is shockingly good in low to mid noise levels – as in it eliminates the background noise while not taking away chunks of my voice. I haven’t tested in very noisy environments.
Battery life is exactly as advertised (4-hour playtime) – I haven’t worn it out, so I don’t know the longevity.
Its battery hasn’t exploded, and I’d love to hear from anyone who may have had any problems with it (I don’t distrust this particular brand, but there have been many battery issues with Samsung etc., so I just put it here in case)