Easy & convenient!
This is an easy to use product especially compared to the whitening strips.  Just turn the pen clockwise to open.  I had no sensitivity with my teeth but I found it helpful to put something on my lips.  I have lots of crowns & obviously the color on them can’t be changed. I would recommend this product.  In fact there are 4 pens, enough to share 2 with my husband & still do occasional touch ups.
Rating: 5 stars