I THINK that is the dimensions. Has anyone tried one???? It looks to be the same size as the coil that comes standard on the ACE250's. I wonder how it handles the extry power coming from the AT Pro in Pro mode??? Has anyone combed a spot with the DD coils only to go back with the Concentric coil and find stuff?? Thanks for any input. By the way, I have the 5x8 DD coil and LOVE it in trash and nails,