upgraded its motor, its real output speed is from 500 rmp to 1200 rpm, become faster, stronger and more efficient.REPLACEABLE SANDPAPER DISCS -- self-adhesive sanding discs, easy to paste and remove, one person one disc, healthier and sanitary, perfect for nail salon or family use.ADJUSTABLE SPEED -- equipped with independent speed controller, you can adjust a variety of speeds, better than other brands (they only provide two levels speeds).NOT BATTERY OPERATED -- no need battery, just need to plug in and set suitable speed, you can use it at once No need to worry about low battery any more.DURABLE METAL BODY, NICE POLISHED -- 360 degree rotating, it is not only looks very pretty, but also can fast remove men women foot heel cracked, dry, dead skin, calluses etc. Product description KEY ADVANTAGES: SPEED ADJUSTABLE --- You can try all kinds of speeds, different from other machine (they only provide two levels speeds). NOT BATTERY OPERATED -- -No need to worry low battery again SANDPAPER DISK REPLACEABLE --- One people one disk, safe and sanitary. METAL BODY SHELL --- Durable to use, long lasting. NICE POLISHED SURFACE --- Touch comfortable well. PRODUCT SPECIFICATION: Rated voltage: DC 24 V, Rated current: 1.5 A Output speed range: 0-1200 rpm Electronic foot file size: about 4.56x1.69 inch Electronic foot file weight: 5.99 oz. PLEASE NOTE: DO NOT USE WATER TO WASH THIS ELECTRIC PEDICURE CALLUS REMOVER HOW TO USE ELECTRIC CALLUS REMOVER MACHINE? Preparation works: we need to soak our foot for 20-30 minutes with warm water, to soften feet dead skin. Step 1, tear off the protective film of sandpaper disk. Step 2, paste it on the machine well. Step 3, connect the supply cord and plug into the outlet. Step 4, turn on switch and adjust suitable speed you need. Step 5, in the operation, you can apply appropriate pressure, not too much, or the machine will be damaged. Step 6, after using, remove sandpaper disk and clean machine with dry cloth. This machine is not waterproof, please be attention. Step 7, apply foot cream to care foot. PLEASE NOTE: THIS ELECTRIC CALLUS REMOVER MACHINE IS NOT WATERPROOF