was similar to the 1941 Mystery Dial model, but there was only one cipher setting window, labeled "Master Code." By late 1944, Ovaltine scraped together enough material to manufacture another Code-O-Graph, the 1945 "Magni-Magic" Code-O-Graph. This unit used stamped sheet steel for the badge bodies, painted with "gold" paint to look similar to the earlier brass badges. The cipher disk element was made of injection-molded plastic, with the center of the disk knob in the form of a magnifying lens. The production was limited, and it was the only model of which supplies were completely exhausted. The 1945 model altered the cipher-key setting scheme. The new method was to align one of the letters on the alphabet scale to a numeral on the number scale. For instance, the "Master Code X-15" setting meant that the letter X would be moved until it was next to the number 15 on the number scale. The advantage with the new scheme was that a total of 676 possible key setting combinations could be used. The disadvantage was that each key compromised one letter-number pair. The 1946 model was the "Mirro-Flash" unit, the first postwar Code-O-Graph, and the last in badge form. Since the war had ended, the new badge was made of stamped sheet brass, and the plastic "dial" element had a small circular mirror for signaling by heliography. It used the same cipher-key setting methodology as its immediate predecessor. This practice was used for the 1947 and 1949 models as well. The 1947 model was the first in non-badge form. It was in the shape of a police-style whistle, with the cipher elements along one side. It was called the "Whistle Code-O-Graph," possibly the least imaginative name of the series. The 1948 model, the "Mirro-Magic" unit, was a circular product, manufactured of brass, aluminum, plastic, and steel. The cipher letters and numbers could only be seen one at a time through windows on the front. The design had the cipher alphabet and number disks coupled by friction, and there was often slippage when trying to decipher a message. Unlike any other Code-O-Graph, the cipher-key settings utilized a pointer on the back, and a number scale from 1 through 26. Each would increment the positioning of the two scales. The last Code-O-Graph was the "Key-O-Matic" unit. Possibly to compensate for the slippage of the 1948 unit's elements, the cipher alphabet and number scales