Hi
Note this part with "rundell" was see too in "prufgerat ", part 11, perhaps the reason for red brown colour.
Note sometimes red/ brown paint was under blue grey luft.
This prüfgerat was used with kompass (harisson explanation is ok)
- Same part perhaps but without "rundell" coming frome one Do 217 N1 Photo one
- Plug in Prufgerat photo two in thumbnail
Amic, Dan