I think we have talked about this before, but I am gonna have it done through the dentist. I go back on the 11th for an impression and then go back to get my trays and tubes with the whitener. She said I get 12 tubes- 6 are 10% and 6 are 15%. Each tube does 2 to 3 treatments. She said I will use enough probably for two weeks and then have enough left to do touch ups for about two years. Then I can just buy the refills. For $250 and the fact that I have not smoked in almost five years I think I earned the treat! See they look whiter already!