Usage Tips:REPLACEABLE SANDPAPER DISCS: This electric foot file includes 60pcs self-adhesive replacement pads, one person one sanding pad, avoid bacterial infection, safe &; hygienic!SPEED ADJUSTABLE: This foot file hard skin remover machine has independent speed controller, so you can easily to control its speed as your request, fast or slow, more convenient.NO NEED BATTERY: different from traditional pedicure foot file, this device is not battery operated (just plug into a socket and you can use it immediately), no need worry about low battery again!ADOPT POWERFUL MOTOR, 360 degree rotating to remove foot heel cracked, dry, dead skin, calluses. (PLEASE NOTE: BEFORE USING MACHINE, WE NEED TO SOAK OUR FOOT FOR 20-30 MINUTES WITH WARM WATER, TO SOFTEN FEET DEAD SKIN.)COMPACT &; PORTABLE: This foot file callus remover machine is just like a small flashlight, portable and lightweight, with nice polished alloy surface, looks more beautiful and elegant.