The dimensions are: 1" tall x 1" wide x 3/32" thick. The chain is the beaded "dog tag" type. Image available for licensing.
The design consists of an octagon shaped background which represents a ?STOP SIGN", the NA for "NEVER AGAIN", and the Magen or ?Star? of David, which is not only the national icon of the State of Israel but also symbolic of the ?YELLOW STAR" worn on the clothing of, and used to identify Jews, during the Holocaust.