Features: It can automatically emit ultrasonic wavesat a speed of more than 35miles per hour during the day or night, and warn deer 1/4mile away. The purpose of deer whistle is to stop deer from running in front of your vehicle. Each whistle is equipped with anextra adhesive pad for replacement. We upgraded theordinary double-sided tape to a very strong tape, which can be kept in place even after professional car washing. The equipment is made of high-quality plastic, which can resist all weather, even if it is extremely hot outdoors or belows freezingpoint, it can work normally. Just tear off the tape cover and stick the device on the bumpers or grille. Whistle can be easily taken off the base to washthe car. Specifications: Material:ABS Size:Approx.5x2.3x2cm/1.96x0.9x0.78inch Color:Black/Silver Package Includes: 2x Animal Alarms note: ①.Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. ②.Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thanks for your understandings.