20 Pouches: Each with 1 upper & 1 lower strip (40 total strips). Enamel safe formula. Professional level whitening at home. No. 1 dentist recommended brand. Enamel safe. Same whitening ingredient dentists use. Thin, comfortable strips that mold to the unique shape of your teeth. Advanced strips for faster whitening. Crest's highest level of whitening at retail. Whiter teeth for 18 months.