Germany. An NSFK Membership & Sponsor Badge

A NSFK (National Socialist Flyer’s Corps/Nationalsozialistisches Fliegerkorps) membership/sponsor badge; in aluminium; horizontal pinback; obverse marked with a small “F” standing for “Förderer/Sponsor”; maker marked but illegible; measuring 21.51 mm in diameter; marked “Ges. Gesch.” on the reverse; in overall very fine condition.