Brilliant for our two guinea pigs. We bought two packs of this to allow more running space. So far we've only made a big rectangle from it with the odd corner having one piece connected so that we can hang treats from it. It is really sturdy when up and compact when put away again. 
We put it on the floor in our living room so that the piggies can have a good run around, which the can't really do in their cage, even though it's of a really good size. We bought a plastic water bottle to attach as a glass one was too heavy for the run. 
We have two very happy, safe and tired out little guinea pigs, we plan on putting it on the grass in the summer so they can enjoy it even more.
Great value for money and cheapest we found anywhere, it was reduced in price so win win for us and the piggies.