Oooh, this is fun!  The 1930s equivalent of texting your husband a grocery list!  There are 40 different grocery items engraved into the metal.  The teeny iron levers indicate you're running low - all levers still attached and in working order.  
 
Identical one sold at auction for $350 recently.  See a fun Daily Mail article here about this unusual piece.
 
I feel tempted to wear it as a necklace for some reason!
 
Brass and iron
1.75" x 2.5"
Red back
(2) holes top and bottom