K&H Pet Products Outdoor Heated Dog Pad - Medium 19"x24" - Weatherproof & Energy Efficient Pet Heating Mat for Dogs - Perfect for Dog Houses, Garages & Cold Weather Use

My cats love these things!!! It says they are for outdoors, but I have them indoors. I love that they don't get too warm as to hurt my pets (human heating pads get so hot!) and I love even more that they are pressure-activated so I don't have to worry about them when I am not home.***Make sure you read the instructions when you first get them. You have to inflate them a little then push the air out. I completely forgot to do that with the first one I had. While I didn't have any problems, you should probably follow the instructions.****My kitties like to lay on cat beds I have near the windows, and the windows can get cold in the winter, so once winter rolls around I put on of these on top of the cat bed. During the summer when the window is open it is too hot so I put it someplace else. The other one I have is not near a window and I leave it out year-round (my cats sleep on them regularly any time of the year).They come with these wooly covers which is nice, but I have found one of my cats doesn't like the wooly cover. So I put old pillowcases on them which works great and makes cleaning a breeze.I bought my first one (see pics - the one in the blue pillowcase by the window) in late 2012 and I have no problems with it. It is still performing well after 2+ years of regular use. It is a size small and as you can see my 10 lb average size DSH has to curl up some to have his whole body warmed by it, however he enjoys laying with the middle of his body on it and his head and feet off which I presume is to cool off a little.I bought the second one (in the tan pillowcase) in early November of last year and have loved it as well. It is the medium size. Larry can stretch out comfortably on that one without it being too big. My younger cat Lucy decided to start tearing up the pillowcase as you can see in the picture, but the casing for it is sturdy and she didn't damage it at all.These are a bit pricey but well worth the price as they are well made. I don't use them outside so I can't speak to that, but I'm sure they would do well for that too. If you want to spoil your special little babies, they will love you for this! Also, if you have multiple pets and find them fighting near the beds, they are fighting over who gets to use it and and you'll probably have to get a second one. My kitties were not good at sharing and getting a second one restored the peace.