This device is an S-TEC Corporation aircraft autopilot roll or trim servo assembly designed for general aviation aircraft. Weighing 2.9 pounds, the unit converts electrical commands from the cockpit's autopilot computer into physical control surface corrections. It features an open metallic capstan drum wrapped with stainless steel bridle cable to interface directly with the aircraft's control cables. The hardware concludes with an integrated electrical harness terminating in a standard 9-pin D-sub connector for system telemetry and power input.