I have to admit I was a little skeptical about this purchase but I needed something small and easy for my 4 year old to work on on her own. I bought only one, but I’ll definitely be ordering the full set again. This is such a great product! I love the disappearing ink: endless work for her to do without a million papers to tear our and keep or toss. The grooves: seriously therapeutic! I played with it for like 20 minutes straight before I ever gave it to her. And obviously it’s great for muscle ...