Cat Door Recommendations with Sensor?

[lulusong]

I have 3 cats. Only one is allowed outside (a rescue that was just too old to acclimate to indoors only). I'd like a cat door that

a. will only open/close for cat with the the sensor on collar (the one door on amazon that's highly rated only needs a sensor for cat to go in, but any cat can go out -- not sure why anyone would need that!)
b. is raccoon proof

My beloved Amazon has yielded nothing, so I hope someone here has an idea. TIA.

[Anonymous]

They allow any cat to get out in cases of fire and stuff (carbon monoxide,etc). You don't want them blocked when it's dangerous inside.

It's pretty hard to be raccoon proof. They use their hands/paws and brains. Something motorized with metal/thick wood doors, maybe...