Opalescence Go 15 is a transparent whitening gel that contains 15% hydrogen peroxide for professional-grade tooth whitening. You can wear Opalescence Go 15 for 15 to 20 minutes per day. Product details: Opalescence Go is the perfect option for patients who are looking for convenient, ready-to-go whitening. A professional whitening gel delivered in pre-filled, disposable trays, Opalescence Go features the enhanced UltraFit™ tray and can deliver dramatic results in as little as 15 minutes per day. The UltraFit tray sets Opalescence Go apart with its unique material that warms with the temperature of the body so that it comfortably molds and adapts to any patient’s smile for an even more effective and enjoyable whitening experience. With no impressions, models, or lab time required, Opalescence Go is the professional alternative to less-effective over-the-counter options and is an excellent introduction to whitening as well as a perfect follow-up to in-office whitening. What's in the box: One package contains 4 upper and 4 lower trays of Opalescence Go 15 advanced tooth-whitening gel We store every item in a temperature-controlled environment for freshness. You will want to store in the refrigerator as well.