Purchased at a shop in Reiwa 4 (2022) Length: 50 cm It didn't suit me. I wore it during exercise, but as time passed, my upper body felt heavy and my neck became stiff. When I wore two with color balls, my upper body became stiff and it didn't improve my performance. It seems that there are differences in whether it suits people, so please research well before purchasing. (I feel like it's not something that alleviates shoulder and neck pain.) Perhaps it's for improving the exercise performance of those who don't have injuries? By the way, for pain relief, Colantotte worked perfectly for me.