Air fieldpost cover with Agram overprint in blue-black, letter handstamp FP.No. 58391 C, 2nd Company of XI Fortress Infantry Battalion 999, Kos Island, good commercially used condition, stamp and cover with transit wear. Stamp remained uncancelled. Cover flown out by the Vienna air fieldpost control office; sender demonstrably stationed on Kos until war's end, photo certificate Gustav Mogler BPP (1983).