Airspeed / Machspeed Indicator Kollsman AN5863T4 F4U-5N Corsair
Here is a combination Airspeed Machspeed Indicator, 0-650 Knots, made by Kollsman, as used in the US Navy's F4U-5N Corsair per its parts manual dated 1951. The mach number is adjusted for the aircraft with a hex key turning the blue screw on the rear case. NOTE: The striped airspeed limit pointer is present, but the airspeed pointer is missing. Measures 3.25 inches diameter and 4.25 inches deep.