Several years ago, I started buying a similar product ( same ingredient, same strength, same company) from my dentist....for about three times the price! This stuff works, without a doubt. I have the professionally fitted whitening trays, and with this product, I can get my teeth to look almost TOO white. Be careful how strong a concentration you use, though, bc it can make your gums sting for a day or so. That happened to me after the third application with this 22%, but for me its worth it bc I love the results.

Day/Night video resolution is spectacular with both Front & Rear cameras but, as mentioned by several others, the manual is atrocious to decifer. I even went into Google Translate to try and get a better rendition of Chinese->English and it was almost a word-for-word translation. Therefore, the learning curve for adjusting things in the Menu is very steep although not insurmountable. To that end, I have a blinking red light on the LCD screen now and have absolutely no idea what it means or why it's there.

This whole line is a joke. Any review with more than 1 star is OBVIOUSLY a person trying to sell this stuff ( hence the email addresses added to the end of the "great" reviews) i paid over $60 for 4 masks and it did absolutely NOTHING to my skin. DON'T waste your hard earned money on this garbage. Everyone is trying to make a buck off this crap and i somehow got roped into it. Ill stick to the SK-II masks they actually work!