Large 2.5" button made by W&H. This is the earliest "National Air Race" we know of and the only example we've seen. Center text around bi-plane reads "Official Guest." This button is from the estate of aviation engineer and inventor Carl B. Chupp who acquired this button as a child at this event. Also see his personal items number 633-635. Button has small bit of tone on the off white areas at extreme left and right but very minor. An exceptional rarity for both the aviation and the exposition collector.