6X Deer Whistles Wildlife Warning Device Animal Sonic Alert Car Safety Accessory ! Now you can greatly reduce the risk of animal/auto collisions with this lot of 6 universal sonic whistles! These wind activated whistles feature: • Alert animals up to 1/4 mile away of your approaching vehicle. • Provide safety for you and your passengers. • Mount easily with adhesive backing. • Fit all trucks, motorcycles, cars, vans and SUV's. • Dimensions: 1.93" L x 1.60" H • Emit ultrasonic sound waves inaudible to humans or pets inside the car. • Sonic warning works automatically day or night at speeds over 35 mph. Air flows in and high frequency sound waves warn animals away!