MAXX, In-Office, Whitening System, 25% Active Blend, 5-Patient Kits, A126250About this product containing 35% Hydrogen Peroxide it does not cause sensitivity after bleaching (more than 30%) prevents demineralization of enamel performs whitening without the use of light In just one 40 minute session patients see a change of 2 10+ shades with no custom trays. All Natural with limited sensitivity. All Single Patient Kits come with 3ml of Pre Whitening Prophy Paste + 3ml of Post Care Whitening Gel.