Best Pet. I got a 24 inch high, 8 panel with door for $40.00 on ebay. I love it. It's strong enough that pups can't knock it over, and you can make it smaller if you want to take the pups to a show. I put it at the end of the whelping box so when it's time to potty, pups jump out of box into xpen.
I built my vinyl lattice/pvc pipe pen several years ago and it is still like new and easy to clean. It's also easy to take down for storage. Email me and I will send you pictures.
