Downrods, or ceiling fan mounting rods, allow a ceiling fan to be mounted on either a vaulted or flat ceiling and are available up to 72 inches long.
Ceiling Fan Sizes There are four common ceiling fan sizes that you will find when browsing for the perfect ceiling fan for your room: small, medium, large, and great.
Other important considerations for your bathroom fan, aside from size, are wet and damp ratings.
There should be a white, copper or green, and black wire coming out of the ceiling's electrical box.