The Little Millionaire Savings Bank is a classic "puzzle bank" with a rich history and unique mechanical design.   Produced by the Vertago Manufacturing Company based out of Boston.  These popular novelty banks were manufactured during the 1920s.  They were often custom-stamped on the top or side with a local bank's name (like a neighborhood trust or state bank) and given to children to encourage early savings habits. 
 
Lettered Dial: The combination relies on a two-letter code using the indexed alphabet ring stamped around the middle. The dial omits the letter "Q" entirely (running A through U). 
The "Blind" Opening Method: If you do not have the code, you can find it by applying gentle upward tension to the top half of the barrel while slowly spinning the dial. You will feel a distinct mechanical "click" or a small amount of physical give when you pass over each of the two correct combination letters.
Internal Storage: Once the two letters are correctly aligned with the indicator arrow, the top section pulls straight up and out, revealing a small nested metal coin tray inside
Constructed of solid tempered steel with a protective nickel coating.
2 7/8 inches tall with a 2-inch diameter barrel shape.
The top slot features internal anti-tamper metal flaps. These prevent coins from being shaken or pried back out once deposited.