This callus remover is a great value for the money. I went from 2 hours of foot exfoliating in one sitting to 4-5 mins a day after shower. I wouldn't use this in the shower. The charging outlet didn't have a waterproofing door and the gear is exposed. It wouldn't be wise to test there up rating. Those that are complaining that the wheel is stopping or it doesn't have enough power probably never have a true profession exfoliate their feet. Power sanders aren't necessary for your feet. Soak your feet Dry with a towel. When the calluses on your feet or hands look white, start sanding. When the exploited skin cells become a dry powder then soak again and switch to the other foot. Take your time and take off in layers. You don't have to pushpress this exfoliator at all. Gently lay it on your foot and guide while it's doing it's job. DON'T FORCE! If the battery starts to shorten after 8 or 9 months then buy another one or sauder a new battery in it. Think of all the time and money you saved by investing $13.00. Best investment every and my feet are baby soft. I haven't worn sandals in 24 years!!!