This is a job-lot of three, circa 1980s vintage, NOS - new-old-stock, 52 mm diameter, VDO Cockpit 0~6000 rpm alternator-sensed engine-tachometers.
First Marked: 230/105/3 | 12V | 993 1660 Hz | massefrei | 10.86 | justierbar | NO2 10.86
Second Marked: 230/105/3 | 12V | 993 1660 Hz | massefrei | 10.86 | justierbar | NO2 10.86
Third Marked: 333/230/105/3 | 12V/993 1660 Hz | 2.87 | justierbar | masseFrei | NO2 2.87
I intend to use one of these in my VW Type 4 engine, British specification, 1973 VW "1600" Type 2 Westfalia Continental campervan, for which I have already incorporated a W-terminal into the Bosch 55A alternator.
At sometime in the future, I shall probably sell one or both surplus VDO Cockpit 52 mm tachometers
There is also VDO Cockpit "Night Design" 52 mm tachometer
For those who seek something more in the style of the 1968~73 VW Type 2 factory-fitted instrumentation, there is or was a combination tachometer & oil-temperature indicator.
On the right-hand side of the instrument panel, retro-fitted by Jürgen Bolle, to a German specification, Deutches Bundeswehr (i.e. German Army), 1972 VW 1600 Type 2 Kombi, is an ONG (i.e. Okaser Nöte Gard) brand, combined 250~6500 rpm tachometer & colour-zoned oil-temperature indicator (appears to have blue, green & red coloured zones, indicating cold, normal & hot), of identical style, to that of the stock, factory-fitted, VDO speedometer and combined fuel gauge & warning-light cluster.
For anyone seeking to maintain a stock, unmodified appearance, to their vehicle, this would be an ideal way of gaining the advantages of supplementary instrumentation. I conducted an Internet search for ONG instruments or gauges, to find out more about the company, but drew a blank. Perhaps one of you might have more luck!?!
For more information and illustrations, regarding this military specification, 1972 VW 1600 type 2, refer to the following magazine article:
David Eccles & Andreas Plogmaker, "Atten-Shun! Herr Oberst Reporting for duty", Volkswagen Camper & Commercial, Issue 14, Spring 2004, Pages 22, 23 & 25.