In-office Whitening Kit : 2 0.96 mL Hydrogen Peroxide, 2 0.24 mL Activator, 1 1.2 mL Gingival Barrier, 5 22 ga Flock Tips, 2 20 ga Black Mini Tips. Three or four 15-minute in-office treatments with 38% hydrogen peroxide gel. Syringe-to-syringe mixing chemically activates the product, ensures a thorough mix and provides maximum freshness. Contains potassium nitrate which helps decrease sensitivity associated with bleaching. For best results, follow in-office treatment with Venus White Pro, custom take-home whitening, or Venus White Ultra, pre-filled, disposable whitening trays. Venus Comfort Gel is available separately and contains potassium nitrate and fluoride.