I moved into a new apartment just over a week ago, and I have a dryer with the normal US 220V 3 prong plug that dryers use. My new place has a 4 prong thing to plug into. I googled and came up with this from http://www.soundhome.com/consult/391to400.shtml : Well I'm not hiring "a licensed electrical contractor", so does anyone know what is needed to be done? Are the 4 prong for different amperages than the 3? I imagine so, but this 4 prong one is specifically for a dryer. I'm renting through a realtor that handles a lot of rental places and they have washer and dryers you can rent from them for $35 a month, so I'm thinking they made this a 4 prong one so people won't buy a cheap used 3 prong one and will instead rent one from them.