telefunken ZM1020 The ZM1020 is a top-view Nixie tube with a red coating to increase contrast. This one was made by Telefunken. It is one of many tube types with a B13B base. ZM1212 The ZM1212 from Telefunken is a medium-sized side-view nixie tube. The anode is made up of very fine horizontal wires, which lends it a very distinctive appearance. ZM1370 The Telefunken ZM1370 Varisymbol planar neon display. Telefunken briefly manufactured this and the ZM1350. It is a 15 segment display.