Germany, NSFK. A Free Balloon Pilots Badge

Badge in zinc, silvered, solid construction 44.6mm(width) x 58.7mm(height), weighs 34.3 grams, the top over Icarus head (where NSFK letters were) had been ground out, otherwise in extremely fine condition; numbered on reverse (this number indicate contract number, and it is not award number). A rare badge.