Compatible: all Cars, SUV, Truck, Motorcycle and ATV. About 6 Pair of Save a Deer Whistles Deer Warning Devices for Cars and Motorcycles If you have to drive through areas where there are free range cattle and wild animals quite often or you live in an are highly populated with deer. If you want to save a deer and save your life. The deer warning whistles are a must for animals from the traffic. Get Attention and Save a Deer When your car is moving at 30 or faster, the deer warning whistles can automatically Color: Black Material:ABS size:5*3.5*2cm Package Contents: 6 * open whistle 6 * close whistle Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.