While it is well made, it doesn't get a higher rating because the curve and angle of the balls is just not right. Pulling on the ring in any direction ends up pivoting the thing and therefore digging in to whatever spot it is occupying just then...and it's been tried on several people. I'm going to buy something with the curve being a full, larger, parallel "U" shape.
Despite that it takes a bit of getting used to on the largest ball, it's still a comfortable fit that works perfectly fine for our needs. It took a while to show up, but hey, international shipping is what it is.