When my original one finally died after probably 10 years of service, I tried to find the same thing only to find they have changed the style and the new ones are horrible. I was able to locate my old style on Amazon. This one really does work with minimum upkeep. I have two cats. Works for a week long vacation with two cats. Wish they would go back to manufacturing this style. Tried other brands and nothing else worked well, just this particular model.