Moving at 35 mph or more, this wildlife warning device is wind activated to emit ultrasonic sound waves. Although inaudible to humans, animals are warned of an oncoming vehicle. It comes with adhesive backing and installation instructions. Comes in blister card package. Measurements are 1 9/16 in tall, 1 7/8 in long, mounting foot is 1 7/16 in x 11/16 in , and the wind opening is 1 in x 7/8 in .