Great device, but a`weng weak in the chest. Therefore tuning: have the role with sandpaper (metal, 80 grain) covered (old sandpaper can be easily removed) and place 2 accus with a 2850 mAh. Now there you go like Schmidt's cat: my feet baby soft. Class, I can only recommend, especially because the refill unfortunately is very expensive and the grains are ground quickly.
