Pack-4 Car Deer Warning Devices, ABS Deer Whistles Repeller, Ultrasonic Animal Alarms, Universal Safety Auxiliary Accessory, Compatible with Most Car Models (Silver)

Installed them on my bumper - going down the highway there were 2 cars about 1/4 mile in front of my car - came up on about 4 or 5 deer grazing in a wooded area - got to about 60 yards and the deer stopped grazing and started staring at my car - go to about 30 yards and deer started bolting into the forest - can only assume that since they weren’t bothered by the other cars and their reaction to my car it was because of these

I don’t like the fact that the silver part sliped off and all that is left us the black base that glues on the vehicle.