a b c
  1. a) Type of signal lamp according to catalogue
  2. b) Rated voltage (value and type AC, DC)
  3. c) For special versions symbol W/3 is necessary (no symbol for normal version N/2)

Example of order:
Signal lamp NEF30-LStz/230V:

Signal lamp O30 type NEF30-LSt, with bulb and transformer, colour of shade green, voltage of transformer's primary winding 230V, normal version.