My 2 cents is to stay away from the crappy extension cords sold by WalMart and Dollar [tree,store,etc,etc]. You will notice that the female outlet end is made of a cheap hard plastic that can easily crack and/or fill up with water. Fork out the extra $.25 for cords from Lowes or Home Depot with the hard rubber ends. They have cases of them left over from Christmas...I just bought a bunch more for $1.49 each. And that hard rubber holds ink from a sharpie very nicely for numbering.