... and main control box, thus can be easily installed on trucks, long vehicles, pick ups, buses, etc. ◊ Signal transferred ... (soak proof), can be mounted in any places on trucks. ◊ 4 digital ultrasonic sensors, very stable and accurate, no false alarming ... . ◊ Sensors are with soft rubber rounding, especially suitable for trucks with fierce vibration cirumstances. ◊ All wire sockets are waterproof, ...