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. Pictures posted on jb-electronics.de show a clear GR10H revealing that, like the STC GN-1, the digits are connected to the tube’s pins via thick wires.

Unfortunately, this particular unit shows significant wear and requires increased current to maintain a stable discharge.