This instrument equipped with built-in audible and visual stall warning indicators. In addi- tion to the audible horn, the stall tone output is available to mix with radio/intercom audio so that a pilot wearing a headset can hear the warning. A self-dimming cockpit display indicates angle of attack on a multi-color LED (Light Emmiting Diode) vertical bar graph. The instrument operates on 12 volts, drawing less than 1/5 amp. The cockpit display is a vertical form 15/16" wide by 3-3/4" high. Brackets and hardware are included for pitot or independent mounting of the airstream vane. An aircraft stalls at a constant angle of attack regardless of weight, altitude, temperature or center of gravity, and bank angle. Other parameters such as best lift to drag, best glide, and maximum endurance also occur at known alphas. This instrument, designed by a former McDonnell flight test engineer, will allow you to use alpha to control your aircraft. Excellent use on experimental aircraft.