1" with covered tin back and horizontal pin. Light oxidation over the reverse metal but the front is extremely clean with just the slightest hint of a few pale gray marks to the left and right of his photo. In 1929 Mamer and his mechanic Art Walker flew from Spokane to San Francisco and onto New York and back to Spokane all in five days without ever landing. They refueled in midair. That set a world record for a non-stop flight, the first transcontinental refueling flight, the first night refueling flight, and the first aerial refueling conducted above 8,000 feet. In 1938 Mamer died in a crash of a Lockheed Model 14H Super Electra when the plane went into a drive and crashed near Bozeman, Montana. Investigation revealed a design flaw. Button is likely from the time of the dedication of a huge Nick Mamer Memorial Clock dedicated in 1939 at the Felts Field in Spokane. One seen.