Falcon Gauge Directional Gyro is a gyroscopic navigation instrument designed to provide the pilot a constant directional reference that is not subject to characteristics of a magnetic compass that cause errors. The vacuum type is operated by the air flow generated by the aircraft’s vacuum system while the electrical type is operated by the aircraft’s power supply.The Electrical Gyro is a revolutionary new design. It features: Convenient heading indicator:Gyro automatic corrects its reset. It does not need the pilot to push to reset every 10 minutes:External and internal antivibration systems:Warning flag to inform you when the unit becomes underpowered. Must order 4 pin Connector seperatly P/N MS3116E8-4S.