SAVING LIVES AND PROPERTY: two pair of whistles deer warning devices is . Deer warning can emit ultrasonic automatically day or night at speeds above 35 and will warn deer up to 1/4 mile . The of the deer whistles is to stop the deer from running in front of your vehicle.UPDATE SELF-ADHESION TAPE: We upgraded the normal double-back sticky tape to adhesive tape which is pretty sturdy, they will stay in place even through a professional car wash. And each whistle comes with an additional adhesive pad for replacement.HIGH QUALITY DEER WARNING DEVICE: Made of premium plastic which can resist all weather, even stay at outside extreme heat or freezing, the device can work .QUICK& EASY INSTALL AND REMOVE: Just off the tape cover and stick the device to your bumper or grille. And the whistles can conveniently be removed from base for wash your car. Two deer warning whistles are recommended per vehicle.Product This whistle contains four ultrasonic whistles and four wind whistles. Usually, one ultrasonicwhistle(a whistle with hole in the tail) is matched with one wind whistle(a closed-hole whistle), which is the best effect.Compatible:For The deer whistle warning devices compatible with all , SUV, Truck, Motorcycle and ATV.colour:BlackMaterial:ABSsize:5*3.5*2cmPackage Contents:4* open whistle4* whistleOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.