LASTS 36 MONTHS AND BEYOND with full treatment use. Removes 10 years of tough set-in stains from coffee, wine and smoking. 14 teeth whitening strip treatments, each with 1 upper and 1 lower strip. Blue whitening light included! ** Item has a “best if used by” date of November 2020 This particular kit is RX/ professional strength— not sold in stores. Can only be purchased through a dental professional otherwise.