These two large Isle of Man FDCs are exceptionally rare. The large cover, issued by the Dutch Brigadier Theo Krommenhoek, has only surfaced on eBay a few times over the past few decades, and the Stampex FDC is also a rare find. A smaller Krommenhoek cover was issued with the set of single stamps and is somewhat more common. The large cover, featuring 4-blocks of the set, was produced in very limited quantities.