So why can other people start anything with the device suggests only one Fehlbedinung my opinion. The metal rolls are very robust and also coarse enough abzuhobeln to even the most stubborn cornea. One can only expect miracles. The units are designed in a gentle removal and no grinding machines from hardware store. What people because of distance power demand can be realized only with NEM Bosch sander. My tip. Device fully recharge, but then use with attached power cable. So the small hours long drags with full power. Grind a lot of pressure was only with the coarse roll without. If the pressure is too large slows the resistance only from the roll. When these beautiful runs on speed it takes neatly away what. Then polish with the gentle roll. Important! As the device really millimeters, the cornea removed to form a lot of dust. Therefore something inferior and often beat roll during use and oberflächlcih clean. The device is now been over 2 months every weekend in use until now, no wear on rollers or device discoverable. Very nice also the Lamp LED on the device this.