There are three most common materials used – steel, aluminum, and wood. The steel ones are the most durable and an excellent option for the aggressive dogs. The aluminum kennels are a bit lighter but equally as durable, while the wooden ones look the best but aren’t as safe as the two previous versions. For smaller and not aggressive dogs check top soft-sided crates.
Overview: This best extra large dog crate is accurately labeled “ginormus” because of its huge dimensions. This actually happens to be the crate I keep my dog, Walter, in sometimes. The dimensions are 36” (length) by 23” (width) by 24” (height). So, about 3ft x 2ft x 2ft approximately. These best extra large dog crates are stackable, so if you’re in a situation (perhaps you’re a groomer) where you need to save some space, this crate is workable.
I wish I would have seen the most recent review. Our puppy, key word 4 month old puppy, was able to destroy this defective and cheap product on its third use. We have used many other kennels with this dog and another adult and never had problems before. The seller is expecting me to pay return shipping on a defect item that is now trash so that I can get a refund. Do not buy this product or from this seller. This is definitely not meant for XL dogs as it states since a puppy was able to wreck it.
Addendum added January 28, 2013: My vet had never noticed these carriers because I had never put one up on the exam table until my last vet visit. She looked at it with interest and totally concurred with my opinion of having a small, but open carrier for my two (panicky) cats. She has seen more than a few overheated pets in too enclosed carriers. Since I live far from the vet I always carry spare towels for the bottoms of the carriers and she found that the "stable floor covering'* I use was an additional comfort feature for my pets long trip to their appointments. (I just ordered the larger size of this carrier for my "Phat Kat" and will donate her previous carrier to our local animal shelter.)