Aviation related crash covers are a specialised collecting area of aerophilately and are much-prized items of postal history, because they are generally rare, but as tangible artifacts of often-tragic accidents they have a story to tell. The 367 covers salvaged from the "Hindenburg" disaster are especially desirable, with prices ranging from US$10,000 and up; a cover at the Corinphila auction in May 2001 realized 85,000 Swiss francs (US$75,000).