If we told you we’d have to shoot you – oh what the hell we’ll tell you.
Its a ultra cosmic classified instrument to measure the enthusiasm level of the advanced air show attendee. At the first sight of the attendee’s favourite aircraft the instrument glows red and sends a signal to the organizers who immediately alert the nearest tee shirt vendor to offer the enthusiast their cut rate special embossed tee shirt.
It is called the Tee Shirt Vendometer.
😉