If you download the map files, their default names will follow the following convention:

Congressional District Locator Maps
SS_CDloc.pdf
(e.g. NY_CDloc.pdf)

Wall Map Previews
SS_CD##.gif
(e.g. FL_CD06.gif)

Wall Maps
SS_CD##.pdf
(e.g. CA_CD19.pdf)

SS = 2 character postal code state abbreviation
## = congressional district number