Teeth Whitening Pen Pack of 4 with a Color Card, Professional Teeth Whitening Gel Pen, Quickly Removes Stubborn Stains, Deep Cleans Gums, Safe for Enamel, Whitens Your Teeth 4-8 Shades in 30 Days

These are easy to use and are quite effective. It says to keep the gel on your teeth for less than a minute, but I coated my teeth with it and watched tv for about a quarter of an hour and was quite surprised how it removed most of the yellow tinge from my canines. I've only used it a couple of times, but the first pen still has loads left, so it should last very well.

Not bad. But it is a slow gradual process for it work. No overnight success story. No real aftertaste when using it.Not bad quality but be sure to follow all recommended instructions for it to work properly.Definitely cheaper than having it done professionally.