30 Pfg "balloon trip the air-raid protection division the technical help in need Hamburg", unperforated, horizontal pair - of it the right stamp with plate flaw I "D of the air-raid protection above broken", unused without gumming - alike at that time have become known, it exists according to literature only an unperforated and ungummed sheet of ten, which zetrennt was - from it comes this pair - probably the only one exists, signed Zierer and photo expertize M. Brettl International Association for Philatelie Experts (2016) : "In finest, entirely perfect condition. With the plate flaw very rare. ", Michel for the perforated variety already 3. 200.