Size C-7 and C-9 bulbs came into use in the 1920s. The C-7 1/2 was used much less frequently. The C stands for cone or candle; the number designates the size and shape of the lamp.

As can be seen in the photos, there is some wear to the box. The cover has become detached. The testing of the bulbs was done without removing any of them from the packaging.