I use this device for almost 1 year, and I'm still happy. I generally make a series of 250: 250 to the right, then left, and again 4 times, or 1000 times on each side. It easily takes 40 minutes, and it heats well forearms! There are guitarists who use this kind of device to strengthen their fingers, for me it is the piano, especially the little finger and ring finger. Although 2 kg seem very low, in fact these two fingers there, it's huge! The device is compact, stylish, solid: not a trace of wear after 1 year, while I lug around everywhere. I recommend.