What it is:A set of 10 refill GLO Whitening Gels in the patent-pending G-Vial delivery applicator with the highest and safest percentage of Hydrogen Peroxide gel, with the purest, most potent formulation. Each G-Vial contains enough gel for up to four applications. What it is formulated to do:Unique to GLO it is a highly viscous, thixotropic formula so when applied, it adheres to your teeth without getting on gums and other soft tissue, avoiding the sensitivity common with other whitening methods. Remove a G-Vial's cap and its perfectly shaped tip allows the gel to glide easily over teeth in one quick back-and-forth motion. After applying, use the GLO Brilliant Whitening Mouthpiece to activate the gel's whitening properties. What else you need to know:The GLO Whitening Gel goes on easily, has a fresh mint flavor and is alcohol-free. It stays put on your teeth, does not migrate onto the gums, and does not contain alcohol, which are leading causes of sensitivity. Each G-Vial contains enough whitening gel for four consecutive applications. This is a product refill for use with the GLO Brilliant(TM) Personal Teeth Whitening System. To use the G-Vials, apply a thin layer over your teeth. After one full G-Vial application, you will get more familiar with the application process, making your next session even faster and easier.