Review on Inviguri Cork Yoga Wheel for Back Pain Relief with Spine Groove. 6 INCH & 10 INCH Designs for Effective Trigger Point Release. Made from Natural Cork. by Erika Martin

I was going to love this set of body wheels and at first I liked them but after a few months the cork softened a bit. Everything would be fine if there wasn't one thing - cuts in the big wheel. As you can see in the photo, there are open slots in the sidewall. Compared to the other side, the slots are offset. As you can see in the photo my fingers are in a slot on the back and the support on the opposite side is in the middle of my hand. My guess is that they added these slots to save on shipping weight or material. Whatever the reason, they will eventually cause the wheel to wobble once the cork starts to loosen. I can't even use the larger bike on my back anymore because of the weight on it and the bike wobbling from the misaligned slots. I wish they would leave everything in one piece like a smaller wheel. Unfortunately I spent over $80 on one small wheel, the other became useless for my back. Unfortunately it didn't subside (or enough to notice) until after a few months it was too late to come back. Now I'm hoping for a good deal on chirp wheels again as there are multiple options with that center groove. Update 12/13/20: The seller insisted it was a defect. I ordered another large wheel, same problem with groove misalignment making it unstable.