Can resist extreme outdoor temperatures. The self-adhesive won't harm the bumper.Function The deer whistle is working at the wind speeds above 35 mph, when it working the deer will turn and run away 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 wildlife 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 mph or faster, the deer whistle makes a sound that alerts deer, moose, elk, antelope, and kangaroos. Function: Place two deer wildlife 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 woods. Auto deer whistles will alert animals up to 0.25 mile away of your approaching vehicle. The deer alerts provide safety for you and your passengers. The ultrasonic sound is inaudible to humans or pets inside the car. The deer whistle work on extreme heat and sub-zero temperatures. Installation: Mounting positions for vehicles must always provide for maximum airflow into the whistle. It should provide for the sound to project out of the warning device toward the animals. Optional Mounting Places: You can mount them on the top of the hood as far forward as possible. Non-Recommended Mounting Locations: Behind grill; in the grill; on the end or sides of bumper; on the inner rim of headlights. colour:black Material:plastic size:5*3.3*2cm Package Contents: 6*Wildlife Warning for Auto