Hi there, Google translate says he is spinning 10m. He also has a mild breeze helping him keep some tail lift. I find the 6m dragons most comfortable and the length accommodates circle runs and jumps etc.. 8 might be okay for me but 10m would leave a lot of tail drag. They get heavy after a few minutes of spinning and when I am already tired before practice or performing it's hard to maintain lift so 6m works well and I don't have all that extra fabric dragging on the ground.
