SureFlap DualScan Microchip Cat Door - Door Opening is 4 3/4" H x 5 5/8" W

i LOVE this door! I don't get why anyone would want to return it. It's great to keep your cat safe from wild life (racoons) or strange cats from entering your house or barn. It works off a microchip in your cat and will only open for him/her and then locks behind them. You can program up to something ridiculous like 25 cats. You can manually lock the door (i.e. you are feeding them their evening meal, and want to keep them inside, turn the knob, lock the door). Or you have a wayward cat that hasn't made it home yet, but you don't' want anyone else to leave, turn the knob to "enter only." You have a cat you don't want to go outside ever. You never program their microchip so they can't use the door. This door never failed. It operates on AA batteries and has a low battery power light to warn you. Instructions are simple. If someone returns this door it's because they are lazy and don't want to train their cat on this door. Yes, it takes some of that, but I am here to tell you, invest the time to teach this to your cat, and you will sleep better every night. My cat was skittish of other people. He was a barn cat, but I took the time to let him know me, and he allowed me to train him. He flies through this door faster than a cat doing zoomies in your house now. Best investment i made into my safety, and my cat's safety. Easy to install, sturdy, durable, and great battery life. Yes, there is a click as the door reads your cat's microchip, but that's also a training aid. They learn they have to hear a click and then the door works. And if they are like my cat, who never went through a cat flap till this door, it took him some time to get used to the flap sliding across his back. But cats are smart. They get this. Too bad some people don't.

So I bought one of these a while ago, and after three years I finally went to go install this, originally I thought to do it in a door but now that I have a house I thought 'well, walls are easier to install into and repair than doors, so I will install it in a wall instead!'.Dear reader, it was not easier to install into a wall.In Sureflap's defense, they do mention on the fine print in this page that you will probably need specific accessories for the wall install, they also mention this when you read the installation book. What they do not really make clear is that said accessories are going to cost you 50 or so dollars, increasing depending on the thickness of your wall.So me, I need two extenders (base price 30 dollars each) and the mounting accessory (base price 24 dollars). If you do not have the tape and super glue they want you to use for these accessories, you also have to buy those, as they are not included.So we're up about 75 dollars just because I wanted to install this into a wall instead of a door, and I am doubly frustrated because I could have done the door just fine, but unfortunately had to go through the DIY process of realizing why each of these acessories are needed only after I had cut a hole into my wall. So I am hoping to spare someone else this pain.1. The tunnel extenders purpose are fairly obvious. If you do not use these you are installing the tunnel into anything thicker than about 3 inches, you will have a big gap for bugs and little cat paws and your tunnel will not be supported. Each extender adds an additional two inches to your tunnel. If you are feeling crafty and fruggle you can probably use cardboard and duct tape instead, but it will be a bit of a challenge to make them fit without making the tunnel thicker or thinner, which is going to matter a lot when cutting holes into your walls. Also would not recommend that if you are doing an exterior facing wall. My wall is interior or draft and rain is not a concern.2. The mounting thing I did not understand until I was well into the process of installing. The part of the flap that has all the electronics is meant to only be screwed into from the inside, which means you CANNOT just directly mout it onto yoru wall. As designed, when installing into a door what you are going to do is use a long screw to connect the plastic bracket from the 'exit' flap of the tunnel to the 'entrance' side where the electronics are. This mounts the ends to each other through your door. They include screws long enough for a door so while I imagine it's probably a bit fiddly to get them to line up perfectly, it should work fine. But walls are just too thick for this and the sheet rock around where you have just cut a huge hole is going to be too fragile, so they need another method.But if you foolishly assume 'oh I will be able to just screw the front side of the cat flap into a stud like how I mount literally all other things in my house onto walls', no no dear reader. You cannot. Why not? Who knows. It's not designed for that. It is instead suggested you buy the mounting attachment so that you can mount the cat flap onto the mounting attachment then the mounting attachment onto your door. The mounting attachment is quite large, and I'm going to have to cut into my base board to use it.At the end of the day, I fully admit this is largely my own fault. I am getting pretty used to mounting things onto walls and envisioned a pure and uncomplicated process where this thing that advertises for being a cat door that mounts to a wall is actually equipped to handle a standard wall.It IS apparently doable, but I am getting very tired of spending more and more money to make this work when it really feels like there are much better ways to accomodate this. Why not just let the cat flat mount on the front?On SureFlap's side they do on the wall mounting instructions tell you that 'they recommend using these accessories' and tell you what exactly you should go buy. I do not feel like this Amazon page is very clear about it though. I think it would actually be nice if they potentially had a wall mounting package listed on this listing which will bunder say two extenders and the mounting adapter together, and list one as 'for doors and windows' and the other as 'for walls'. Because unless your wall is no thicker than a standard door this is not going to work without all the accessories, but the accessories are really pretty obscenely priced, especially the tunnel extenders. To be clear they are literally just a thin strip of plastic that fits onto the extisting tunnel.Also, the hole for the cat is pretty small, and the clicking from the locks is pretty loud. I do know I like the SureFlap technology as I have their food bowl and it has worked well over the years.I am only docking one star for all of this because, like I said, mostly my fault. But I don't feel like I'm exceptionally stupid person, I think the frustrations I've encountered are at once avoidable but also understandable, so maybe this information will be helpful to someone else.

We have one big old senior cat (19lbs) who comes and goes as he pleases - he never leaves our yard. We also have a younger, far more adventurous cat that is not allowed out under any circumstances - he will jump the fence in a heartbeat and disappear for two days. So this was a perfect solution for us - with one big question mark. Could our senior cat even fit through the hole? It's a very small opening, and there's only one size to this.I tested him before I bought this door - I cut a flap in a cardboard box and put some treats in it, and he squeezed through just fine. (Ironically, the treats are how he got to be so fat ...)This door was bought to replace a manually operated door, which we used before we got our younger cat. It fit in the same opening, which had been cut into the aluminum panel at the bottom of a storm door. Despite the fact that the instructions cautioned against interference if mounted in metal, it was worth a shot because the hole had already been cut.Mounted like this, the performance was inconsistent - sometimes it worked, sometimes it didn't.I called the company to see if there might be some other cause i could look into - they listened carefully and were very certain that this was the problem. They recommended the circular mounting bracket that will offset the sensors from the metal by an inch or two, which they say is enough. Instead, I found a nice piece of plexiglass in the garage, left over from another project, that I repurposed as a window to replace the aluminum.The installation is very straightforward - but it does require a little bit of skill. Basically, it's "trace the hole, cut the hole, push one end through and stick the other side on with two screws and you're done!", but the trick is in cutting the hole. Initially (with the original door) I just traced the hole and cut it out with a pair of tin snips. The plexiglass was a little trickier. Going through a wall or an exterior door would require some thought for sure.I measured the size and cut the plexiglass on a tablesaw, but I put masking tape on both sides to prevent chipping. Same with the cutout - I traced out the rough size of the opening using the door, then used masking tape on both sides. I made a more accurate line with a marker, drilled a couple of pilot holes and cut the opening out with a jigsaw and a fine-tooth blade.Electronically, it works great. After a little encouragement, our old-timer just sticks his nose up against the little window and we can hear the "click" that unlocks it. I think he has learned to listen for the click himself. We'll see if the other cat figures this out and tries to follow close behind - I wouldn't put it past him.There's a locking mechanism that offers all possibilities. It can be locked both ways, or open one way and locked the other (right now we have some rodents in the yard; we have it set to let him out but not in; we want to check first to see if he's bringing in a mouse or rat). It can also be set to let him in but not back out again - which is great for keeping him in at night. It can also be unlocked both ways for the cat with the right chip, or unlocked and completely overridden to let anyone in or out.Once again, the big downside is the size; it's really tight for our cat. The company assures me that they are "in production" for a larger door, which I will probably buy once it's available.