Hello, I’m new here in the forum, but I’ve been following some posts for some time. My question doesn’t fit directly into this OBD forum, but this department seemed to be the most similar to me;-) We only repair vintage cars, so vehicles that are 50-100 years old, so I often need old test devices. Currently I have this SUN QST 900 ignition tester which actually works without any problems, i.e. ignition time, early adjustment, closing angle etc. he does not assign – see arrows on the photo The upper one is a fixed socket without a rest or similar, so you could not plug in a plug. The lower one can be pulled out with a cable and has a multi-pole connection that reminds of old DIN connections from the HIfi area…. And the half-covered switch at the bottom right (D <--> M) does not open to me either. Does anyone have an idea for what these connections or switches are? Or even better… does someone have a manual of this, or a similar device? We also have other larger testers, but this one only runs on 12V and is therefore also mobile, so I would like to use it. Thanks in advance