I bought the "green" model which is supposed to be "medium" strength. I opened the package, tried it out and it was ridiculously hard to bend, am I am a big guy....6'1 and 190 lbs.Having read other comments here about the quality control being way off, it wasn't surprising. Anyway, I returned it to the seller at my expense "The Therapy Connection" and they said since I "openened" it, it is now "used" and they won't accept it back. They said I should have "tried it while it was inside the plastic"???????? Are they serious? WHAT A RIPOFF!!!!! Now they are unwilling to send this useless piece of junk back to me unless I Pay for shipping again!!!DO NOT ORDER THIS PRODUCT UNLESS YOU ARE 100% SURE YOU KNOW THE COLOR YOU WANT! YOU WILL BE STUCK WITH IT.