I have concerned the right Blackroll me because of back discomfort. This one comes but not so good in the shoulder-neck area, which I found extremely bad. Hence came the duo ball into play. It actually comes quite well in the hard to reach areas with the role. Interestingly, I found that you also can replace the role of the thoracic spine area quite well with him. Thus, a good little alternative when traveling. Overall, I think that's part but very overpriced, with two tennis balls in a sock can be (almost) the same, but tennis balls are a little softer. A star deduction is available for the black coating. I think he's very smooth and slippery by (a tennis ball keeps as much better the position). On smooth ground no chance, even on a carpeted floor, the parts like icicles flutschen it.
I suspect that the larger version is a bit better, this little here may well be replaced with tennis balls in an old sock. But again spend so much money ... nope .....
