The Crankshaft (flywheel) sensor on my 1996 2.0i turbo Break was marked '102340-06'.
It has a resistance of 370 Ohms.
This is almost certainly a Siemens or VDO sensor.
The parts list says my engine (RGX XU10J2TE) needs a 1920 c3 sensor. A unit with 370 Ohm coil.
These sensors are both equivalents, and there are a further 200 numbers from various manufacturers that are apparently suitable replacements.
I was sold an identical looking sensor which had a resistance of 445 ohms. The internal magnet had a different polarity when I tested it with a magnetic compass. I got a refund but the vendor insisted that it was an equivalent.
It was marked 14-43-14 which could be a Bougicord 144314.
As the sensor is difficult to get to, I didn't want to experiment with a possibly incompatible sensor.
How tolerant are engine management units to crankshaft sensors that are slightly different?