Worked for Golden's entire puppyhood!
I bought this crate for a golden retriever puppy while I was at work all day. I had intended for her to make part of it her "potty" since she would be in there for several hours as a small pup, but she never had an accident in it, it basically worked as a large crate. I kept her in it during the day until she was 9 months old (about 45lbs) and she wasn't able to get out. It is very sturdy, even with a 45lb dog jumping on the walls, it never came close to tipping over. It did slide around a bit on hardwood floors, so I had to get a mat to put underneath.

Great for retriever
I originally purchased this pen because I needed a solution for keeping my 90 lb golden retriever contained during our stay with my in-laws. His crate was (42" long) too large to fit in our car rooftop carrier (only allowed about 40"). This fit nicely. It was very easy to set up, and its flexible shape and size worked out very well for the limited space we had in the home we were visiting. It's very well made. While our dog is generally well behaved, he did not try to jump over the pen or knock it over. He quickly adapted to his space when we had to leave him alone. He had no trouble entering through the door of the pen. Now, I have the pen set up in my basement and keep my dog in it during the day while I am at work. It gives him much more room for moving around, playing with toys, eating, drinking, etc. than his crate, and he seems much happier. I highly recommend this pen.

Excellent product
This was one of the best products I purchased for our puppy. Our 6 pound dog is secure in this sturdy pen. We like the easy-to-adjust removable panels and the fact the shape can conform to the space it is in. We have traveled with it as well with no trouble and the door is very handy so that we don't have to bend over to lift the puppy out...even the kids can use it. Highly recommend this product to anyone looking for a good exercise pen for a small dog.

dog pen
We love this product! It's easy to assemble, can be built small or large, is stable enough for our small dog to play and lean up against without fear of it falling. He seems to like being in it because he can see everything around him and doesn't feel alone. The small dog door is adorable! Not sure if this would be appropriate for a large dog, as it might not be stable enough, and the dog door might be too small, but small to medium size dogs could definitely fit very comfortably.

Iris CI Commercial Grade Playpen
I purchased this playpen because I heard it was good for dogs too. I have a 7 year old Jack Russell who pees on everything the minute we leave the house. Now we put him in his playpen in the middle of our kitchen floor and guess what? He doesn't pee! The playpen is really a nice size. We even took two panels off of it. We shape it into a hexagon and he has never tipped it over. It also has a nice little door with locks.Jax also has separation anxiety. It is really nice to leave the house without getting my ankles snapped at. He does have his problems but I still love him dearly.