This Batman key chain from the 1966 TV series, features its stars Adam West & Burt Ward as Batman & Robin on one side and the classic TV show's title card, on the other.
"Holy key chain, Batman !"
It measures at 2 x 3 inches and is about the size of a credit card. It fits fine in a pocket and is easy to find at the bottom of a purse or bag. (Slides easily into your utility belt.) Never lose your keys again!
Note: Image shows both sides of one key chain.