Being a coffee drinker, I try to help my teeth stay white by occasionally using different teeth whitening products. This whitening pen was one of them. Not very much bigger than a regular pen, it is filled with whitening gel that comes out of the sponged tip when you turn the dial on the other end. The treatment takes 14 days; every night before going to bed, you brush your teeth and then use the pen to carefully apply the gel on your teeth (detailed instructions are enclosed). The gel is tasteless, and it does not hurt your teeth. You just apply it and go to bed; it will work on the teeth during the night and disappear by the morning.
I went the whole route, treating my teeth for 14 days, as instructed. My results were very modest. I cannot report "noticeable whitening" the company promises. Yes, my teeth brightened up a bit - but that's all. Definitely not a radical solution, don't be fooled by the show-white smile on the box.