DC12V to 48V backup horn for truck with 3 sound modes1、Premium Material: This reversing alarm is made of ABS material with water resistant shell, resistant to wear, scratch, dust, fade, impact, and oxidation, can work in various temperature environments. 2、Powerful Warning Sound: The car warning horn produces a powerful 112dB buzzing sound, ensuring that no one will ignore this alert when reversing, helping to immediately attract the attention of other drivers and pedestrians, preventing accidents. 3、Versatile Use: Suitable for 12V to 48V heavy duty vehicles and commercial use, the reverse warning alarm is ideal for trucks, cars, excavators, construction machinery, special vehicles, parking lots, and various large container vehicles. Comes with a universal mounting bracket with slotted holes for installation in multiple locations on the vehicle. 4、Easy Installation: Connect the positive screw terminal wire to the reverse light power wire or the reverse switch mounted on the dashboard, then connect the wire to the ground (negative wire). It offers protection in case of reverse or wrong wire connection. 5、3 Adjustable Sound: With 3 different alert sounds to choose from, this reversing backup alarm beeper allows drivers to choose different alarm sound according different scenarios.