Can resist extreme outdoor temperatures.The self-adhesive 't harm the bumper.Function The deer whistle is working at the wind speeds above 35 , when it working the deer will turn and run without being harmed.Installation Just remove the adhesive back and affix the deer alert whistles to the front bumper of the vehicle.Not need electricity Compatible The deer whistle warning devices compatible with all Car, SUV, Truck, Motorcycle and ATV. Save a deer How does it work?When mounted to a vehicle, car or motorcycle moving at 35 or faster, the deer whistle makes a sound that alerts deer, , , antelope, and .Function:Place two deer warning devices on the front bumper of each vehicle.It emits a safe ultrasonic deer warning sound. Deer will hear it and run back into the .Auto deer whistles will alert animals up to 0.25 mile of your approaching vehicle.The deer alerts safety and your passengers.The ultrasonic sound is inaudible to humans or pets inside the car.The deer whistle work on extreme heat and temperatures.Installation:Mounting positions for vehicles must always for maximum into the whistle.It should for the sound to project out of the warning device toward .Optional Mounting :You can mount on the top of the hood as forward as possible.Non-Recommended Mounting Locations:Behind ; in the ; on or sides of bumper; on the inner rim of headlights.colour:blackMaterial:plasticsize:5*3.3*2cmPackage Contents:6* Warning for AutoOnly 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.