2 Wire type.
Works, but is (I assume) resistively incompatible with 1970s Merc- worked fine on a 6" test lead by the engine, occasionally sprang to life in the console, hence no use to me.
Illumination works.
£40 ONO
Apologies for the fuzzy pics, I now know the minimum close range of my camera
If you want a clearer pic, let me know.
