With 4 high sensitive sensors and double CPU/advanced chip set, this system has enhanced coverage and detection ability (0.3 - 2.5m), it can detect small children and low walls as well. This system is anti-freeze and rain proof. Sound alert and digital colored LED display help to provide increased safety for passengers, pedestrians and family members who happen to be around the moving vehicle. The closer the obstacles, the louder and faster the sound alert. A saw drill head is included.