This pen is compact, silver in color and has a soft brush at the tip for smooth and easy application. It has a tooth whitening gel inside it. You have to twist the end to get the gel out. This gel lasts for 4-6 weeks of daily use.
It is very easy to apply and the gel reaches into some deeper areas between my teeth to whiten in there too with the help of the soft brush
I did feel a tingle after I applied it so there is little to no sensitivity at all. I was happy about that however at the same time whitening results are minimal. It does give a clean, fresh feeling though also helps kills bacteria that cause bad breath.
I bought this teeth whitening pen because I have sensitive teeth as well as crowns and this gel is safe to use on that. Like I mentioned before, I have not experienced any sensitivity issues from them after a few uses. I will continue using it to see if my teeth will whiten after regular using.