This little tool is one of my favorites from preschool! You can get a mat just like this from most gym suppliers. I love it much better than the old flat cartwheel mat that used to be used to teach cartwheels. I use it for cartwheels, but also for almost every skill! Here are just a few of the things I use it for in classes:
It also makes a get step stool for the extra little ones for bars, beams, etc.