What: The most advanced technology on the market: the Cozy Kit is waterproof and wireless. Cozy features blue light therapy and dual light therapy. You can receive a whitening session and oral care treatment all in one with our dual light therapy setting. On average each 15 minute session whitens your teeth 2-3 shades lighter. The Cozy Kit has an internal timer that shuts off the device after a 15 minute session and is totally rechargeable.