Opalescence Go take-home whitening system is recommended for patients looking for professional whitening to go or as an alternative to over-the-counter whitening products. With no impressions, models, or lab time required, Opalescence Go whitening trays are also a perfect follow-up to in-office whitening. 6% hydrogen peroxide. Contains PF (potassium nitrate and fluoride). Wear 60-90min for 5-10 days. Melon flavor. Stored in the fridge. Contains 6pcs packages with 20 sets of trays each.