This is a Collector's Postcard for the DC Comics Superhero listed above.  These were released by the USPS when they issued Commemorative stamps for these characters.  The front shows of famous Comic Book issue of the character, the back gives some information on the character and comic book.

The postcard measures roughly 5.25x7.50 inches.  It is in excellent condition.  There are no marks on the surface.  The postcard is unused.  The corners are all clean.  The edges have no nicks or chips.