I came across these in the local pharmacy when living in Hong Kong. I've never tried any teeth whitening products before, and being a coffee addict and (ex) smoker I was keen to try these out. The simplicity of the product is what was most appealing to me (no mucking around with gels and moulds).
There are 2 clear strips per single use; a longer one for the top row of teeth, and a slightly shorter one for the bottom row of teeth. Application is really easy, you simply just peel the strips off and stick them on to your teeth. (I pressed the strip down over one tooth at a time to make sure that the front surface was covered properly and evenly). There is a bit of overhang, but just tuck this under the back side of your teeth.
They do stay on and in place until you peel them off after the 30min processing time. The product on the strips foams up a bit while you have them on. The taste isn't the nicest, but I didn't find it overly strong or unpleasant. I only noticed 'shocks' of pain while wearing the strips - I didn't have any lingering sensitivity at any other time. I used these every evening, after brushing my teeth just before bed. I had noticeable results after about a week, and after completing the full course exactly as advised, my teeth were most definitely white! I couldn't believe the difference when I saw photographs of me smiling.
It's been about a year since I did that first treatment, and I'm really glad that you can purchase these here in NZ (even though they are more than twice the price!), as it's time for a touch up.
I liked that these were easy to use and saw results quite fast. I found that they worked reasonably well for a short period of time but their effects soon wore off. I noticed my teeth were also feeling a lot more sensitive than normal.