"H" is for Hit
Hit cameras are very small film cameras first marketed under the Hit name.
Hit cameras are adorable little cameras, originally made by Tougodo Optical of Japan. They were popular in the 1950s.

This one even bears the Hit name. Hit cameras, however, had lots of different names and are a popular collector’s item.

Here it is with the back open, the film reel removed, and my finger for scale. Now you can see just how tiny it really is!
