I use, and swear by, this brand. They cost more than others but they're made extremely well and are easy to install. I can't image any cat pushing the security door open when it's closed!

You'll want to price shop since some sites beat the Hale site prices. Just compare shipping and return policies.

Also check eBay. There are some listed there and I'll soon be selling one (new) since we thought we'd need a cat door for the shop. The cat ended up in the house instead! :)

I will look it up, thanks!

Ok looked them up- they look like they'd hold up but holy expensive!

I'm going to think about it but do hope to find something under $100. Thanks again.

Here's who I ordered from since they had the best price. I paid $176 for the small-medium size (a $33 upgrade) since I have big cats, but the smaller cat door costs $143 with free shipping. They can be pricey but it's a door you'll never need to replace.

I may just do it. Vet bills are never under $143 and I don't blink at them. Thanks.