Good deal on teeth whitening strips

With all the coffee and tea I drink, my teeth become yellow pretty quickly. I use these Crest 3D White Whitestrips Vivid Plus whitening strips to keep my teeth white. They are usually pretty expensive, but Amazon has a double offer right now: a coupon (click the link on the product page) for $5 off and a code (7CWSVIVIDBF) for another $7 off. The box has 12 treatments.
The strips are clear plastic strips coated with some kind of gooey bleaching agent. They stick easily to your teeth. I put one on my top teeth and another on my bottom teeth and set a timer for 30 minutes. If you're like me, you'll notice a big difference after the first day.
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