Works a lot better than the magnets on a collar, Deb, which my cat consistently lost at $7 a pop. If you have your animal RFID chipped, (which everyone should) why not? The door has a chip reader in it so it will only let in the animal it has "learned" the code for.
The door was sort of expensive, but well worth it as it has definitely prevented us from having raccoons get into the house. We've had it for 4 years and as long as we change the batteries on it regularly, it's worked like a charm.
