We've have one like LJAZ (above) described for our small breed dogs. We've had it for over 20 years, inside and outside. It's never rusted. I think we originally purchased it from PetSmart.
However, in time, "all" our dogs end up on our laps when outside. They also have their own camping chairs, but still end up on our laps. We found attached leashes (so they won't bolt very far) and our laps make the best combination. Funny ... ALL our dogs in 30 plus years of camping, are not happy until they are on our laps. (if only our own kids were THAT affectionate?)