We have been using the ScoopFree Sensitive Crystal litter tray for a couple weeks now and I have been amazed at the elimination of odor I would normally have near the litter box. I love that I no longer have to scoop and look at my cats business everyday. Its amazing how the litter box does all of the work and I only have to dispose of it, what a total game changer! I do have 2 cats and I had to change the tray after 2 weeks. Its amazing.