I bought these for my 5 year old son after he got upset with us for removing a log from the yard that he had been using for a balance beam. He was happy with these as a replacement. They are sturdy enough that an adult (*cough* *cough* me) can play on them but are still very lightweight. I have left them outside since August (it's now November) and they are still in great condition. No fading, cracking or any other signs of weather damage. The kids have a great time rearranging them into different shapes to walk across or jump over. They stack on top of each other which makes it easy to store them in a small place. These would be great for anyone looking for physical activities for their kids to do in small spaces. I have used them on laminate flooring, linoleum tiles, carpet, grass and a wooden deck with no trouble with slipping or flipping that I saw mentioned in other reviews.
We loved them so much that I encouraged our local library to get some. They bought 2 sets and they are a big hit with the kids and parents.