Later the D badge became known as the Silver C, and more often today just the Silver Badge. Earning the Silver C Badge shows that a glider pilot has achieved an altitude gain of at least 1,000 m, made a five-hour duration flight, and has flown cross-country for a straight-line distance of at least 50 km: these three attainments are usually, but not invariably, achieved in separate flights. The first recipients of the Silver C were Wolf Hirth and Robert Kronfeld on 15 February 1931.