The N.I.1 is a numeric end-view nixie tube manufactured by CINTEL (Cinema-Television LTD). It is very old and has hand made numerals. The numerals are made of unusual thick wire. It is stated to be a "CATHOVISOR", a word made from "Cathode" and "Visor". The informations on the tube and box label are filled in and serial numbers seem like to be in the thousands range. Maybe this tubes were a early prototype series. The N.I.1 seems very similar to the G10 from STC.