South Africa 1918 Pretoria Flight Card, 4d Franking, Superb

SA: 1918 "Make your 6d fly". Small Wings PRETORIA FLIGHT card unusually franked KGV 4d tied special AERIAL POST cds 27.NOV, superbly struck. Card is light blue on red print. Addressed to Pretoria, message side blank. Lovely colourful example, VF, scarce upfranked thus.