German Field Phone - for sale - not mine

[HarrySmith]

Just came across this surplus place selling German field phones. Look pretty good but $125.00 each plus shipping I think is a little much.

https://www.sciplus.com/german-military-field-phone-63416-p

Seller Description:  "From the mid-20th-century German military, this is a fully functional field phone. Weighs in at 8.2 lbs, and comes self-contained in a 10-1/4" x 6-3/4" x 4-1/4" dark brown Bakelite case with a handset on a 4-foot cord, a 52" 2-pin jumper, 25" TT plug cord, ringer crank and a battery holder for the pair of D-cells you'll need to add. Side has slots for the carrying cord that we don't have, and the inside lid has a full schematic. Should work with standard stereo speaker wire, and we'd get a pair of these phones if we were you. Small quantity available. These are surplus and have wear and tear on them. We will pick the nicest of the lot."

[countryman]

It's apparently an East German FF63:
https://www.ebay.de/itm/203637728268

Edit to add, here's a manual with diagrams. There's  a transistor amplified microhone!
https://www.klaus-paffenholz.de/bos-funk/ddr/ddr-bilder/ff63.pdf