Fast and easy to use! Safe-developed by dentists. Dries really fast and last about 24 hours depending on use. Will not come off when eating or drinking. Odorless and tasteless! Can be used on nails as well as teeth. Removes with vigorous brushing. Non-toxic and safe. Comes with a Gold vial and a Blackout vial. Mix for a decay color. Includes a tiny applicator.