Electronic pet doors, that can offer safety from intruders and other animals entering their homes are showing up in more and more homes around the world, and as such, there are many pet companies manufacturing them today.
Make sure when buying your electronic doors they are well insulated. Unless you live in a climate that has very pleasant weather year round, if your doors are poorly insulated, you'll be unhappy with them once the cold and wind start coming in. Electronic doors can have different insulation factors, from being very poorly insulated to having such an airtight sealing system that they hold out bitterly cold weather.
Secondly, when purchasing electronic doors, if they are of the electronic flap model, make sure that when they're in auto mode, they lock in the inside to the outside direction. Many electronic flap doors can be manually locked, but do not auto lock in this direction with the theory that the door needs to lock from outside to inside in order to keep out other pets, but there's no reason to lock them in the inside to outside direction unless you specifically want to lock your pet in for some reason. If you think this through, you'll easily see the flaw in this reasoning. Any intruder wanting to come in can pull the flap toward the outside and crawl through and any smart raccoon will soon figure out how to do the same thing. Make absolutely sure the door locks in both directions on auto mode, not just on manual mode.
Thirdly, decide which door is more appealing to you as far as the way the electronics are handled. There are basically two groups in which the electronics fall into. Most of the automatic pet doors in this group work in a very similar fashion, i.e. the magnet or chip unlocks a flap that the pet can then push open and walk through.
The second group powers from an electronic collar worn by the pet that actuates a motor driven panel that raises up into the top of the door panel, lowering and locking it once the pet is through the door.
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