Well our initial experience with the Purrforma (by Petmate) has been a bad one. The unit will not cycle automatically. I should have been suspicious. We bought it at Petco and it looked like the box had been opened. All the parts were there except the instruction manual. Should have known right then. It is supposed to cycle every 20 minutes. It doesn't. So back it goes to Petco. Only problem is that this was the only one they had....