Everyone knows white perfect looking teeth is a huge confidence booster. Although, having and taking care of white teeth is a bit of a handful. Especially, the cost, being time consuming and sometimes causing sensitive teeth. The pen based applicator promises to whiten teeth up to 10 shades in just one pen. Then pen can be used up to 4 times a day but I used mines once a day as you can eat or drink after 30 minutes after application. For some odd reason, when I know I can’t do something I want to do it more. So, I usually apply it before going to bed so I won’t have to worry about it. The company promises whiter teeth in two days but I didn’t notice any whitening after 2 days of using it. Granted, I was applying it less than the recommended dosage but my teeth did get couple of shades lighter but I am not sure if it was 10 shades whiter. I do like the pen applicator you can target the areas more efficiently than with a strip but it does also get a bit more messier than with a strip. I did like how my teeth was whiter with minimal effort and also with no sensitivity.