Size AAA 1.5 volt

Ever Ready AAA
50, 100, etc.
Most early models of Instamatic cameras were fitted with either a two-pin ‘Kodak hotshoe’ (A design only used by Kodak) to allow the fitting of an ‘Instamatic Flasholder’
as with the model ‘50’ or a built-in flash holder as with the model ‘100’. Both of these types required two AAA size batteries to enable the flash to discharge. the cameras would still function without batteries but the flash would not work .
Used in x33 range of cameras, these mercury oxide cell batteries produced 5.6 volts and were used to power thr flash cubs when fitted and in the case of the 333, the CdS cell.