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. Measurements are approximately 1 9/16" tall, 1 7/8" long, mounting foot is 1 7/16" x 11/16", and the wind opening is 1" x 7/8". Comes packaged in a blister pack.