I had been dying to get one of these from the traditional litter box and am SO HAPPY. I have two 4 year old male cats that like to keep their routines. The instructions are very clear and helpful, leaving the new box by the old one (i put this in the place of the old one and the old one a foot away), mixing some of the old litter in the box and the new crystals in the old box, they switched in under a week. The crystals are a weird transition for me because they’re sharp on the floor when you step on them lol but otherwise THRILLED.