PerformAIRE POCKET is a handheld Racing Weather Station that includes ALTRONICS Patented PerformAIRE weather sensing and performance calculating technology. PerformAIRE's Patented calculations are based on measuring horsepower and performance of an internal combustion engine. Ultrasonic technology accurately measures wind speed and gust with no moving parts that can break or wear out. Simply to use Joystick controls all functions. Bright color LED display allows for day and night use. Accurate and Fast response time.