The GC12/4B is a neon-filled counting tube manufactured by ETL in Great Britain, capable of bi-directional operation and up to 4,000 counts per second. It features twelve stable cathodes, unlike the usual ten found in most Dekatrons, allowing it to count in base-12. Four of these cathodes are connected to output pins, enabling them to trigger actions such as advancing another Dekatron when active. Divide-by-12 Dekatrons like the GC12/4B were ideal for timekeeping applications since the division of hours, minutes, and seconds in a day aligns with multiples of twelve.

The GR10H is an early Nixie tube produced by ETL, featuring digits visible through a small viewing window, with the majority of its envelope coated in black paint—likely intended to enhance contrast and minimize light bleed from adjacent tubes. Shown at the end of this page is a transparent GR10H revealing that, like in the STC GN-1, the digits are connected to the tube’s pins via thick wires and an evaporative getter was used.