Listerine Whitening Quick Dissolve strips are just like they say, whitening strips that dissolve while you're wearing them. The strips are not top or bottom specific. They have a notch in them that shows you which way to apply, because the treatment is on one side of the strip.
The first package I opened I actually tore the strip. I think the packaging could be made a bit better to prevent this. Placing the strip on my teeth was tricky because they were like magnets to my teeth and once placed, I could not reposition the strip. The flavor isn't the greatest either. They are described by the company as being Cool Mint in flavor but it was more like plastic with a hint of mint. As the strips dissolve the consistency in your mouth is that of globs on your teeth. These did however prove to whiten my teeth after just two usages. I will continue to use the package I have, but I'm not sure I would repurchase in the future.