Maker's Name: 
3.3 × 3.3 × 8 cm

A screen on the side of the tube has numerals marked 0 to 9. An electron beam within the tube is deflected to illuminate a vertical fluorescent stripe next to the relevant numeral. A series of these tubes were used in a laboratory counter to determine the number of events within a given time period, eg Geiger Counter events.

If the counter were gated to turn on and off for say one second, it could also be used to measure the frequency of a source.