Crest 3D Whitestrips Supreme Professional Exclusive Kit, 4/Case. Includes: 1 light and 42 strips: 21 treatments (each with 1 upper/1 lower). Flexible, thin strips coated in a tooth whitener containing peroxide designed to securely conform to the shape of the teeth and keep the tooth whitener in place. Crest AdvancedSEAL No Slip Technology provides a form fit, no-slip grip that molds and adheres to teeth for a better whitening experience. 4 Patient Kit