Falcon Gauge True Airspeed Indicators have sub-dial and windows. Pilot can set to coincide the outside temperature with the flight altitude for immediate reference. It is a high precision airspeed indicator which makes nice feature and impression for an experimental aircraft cockpit. It also features all parts made with metal, aluminum case housing, short length, light weight. Range: Dual Range- mph inside/knots outside or knots inside/mph outside. Single Range- mph or knots.