Germany. An Rlb (Air Raid Protection League) Visor Cap Eagle Auction with a bluish tinted background and with a bluish tinted background and illustrating two groups of soldiers operating flak guns on the obverse Footnote: The Fairbairn Sykes Fighting Knife is a double edged fighting knife resembling a dagger or poignard with a foil grip developed by William Ewart Fairbairn and Eric Anthony Sykes in Shanghai based on concepts which the two men initiated before the Second World War while serving on the Shanghai Municipal Police in China in overall virtually mint condition the reverse with all three crimped prongs in place one with hot glue remains from previous collector’s mounting