Car 4 probe pure buzzer back-up radar without display [Product content] : 1 host, 4 probes, 1 speaker,Accessories: 1 hole opener, 1 power cord, 1 manual, 2 double-sided adhesive stickers, Principle introduction :The astern radar is composed of ultrasonic sensor, main engine, sound system and so on. When the car reverses, the reversing radar automatically starts to work, the ultrasonic sensor detects the distance between the car and the obstacle, and displays the distance on the screen, while the real voice reports the distance or emits a beeping alarm sound to help the driver understand the obstacle information and reverse easily. Product Features :The simplest installation, strong anti-interference ability. Area detection range :Note: The maximum effective range of astern radar detection is 2.5 meters, for different obstacles, its ultrasonic reflection strength is different, the detection distance is also different. Functional features :1, the automatic detection of obstacles behind the vehicle, automatically open, switch.2, crescent LED heartbeat step by step display function, digital + sound step by step prompt.3, microcomputer intelligent control, accurate digital display obstacle distance, from military technology, accurate and reliable.4, sound +LED high brightness distance prompts, not affected by the environment, rainy days, dark nights are especially advantageous.5, anti-electromagnetic interference, patented technology, international certification. Quality assurance. No impact on the original electronic system.6, the probe adopts embedded installation, multi-color configuration, the sensor is exquisite and small, easy to install. Technical parameters :1. Detection distance: 0.3~2.5m2. Alarm distance: 0.3~1.5m5. Working frequency: 40KHz6. Working voltage: 12V DC7. Current consumption: 20ma-200ma8. Working temperature: -40~809. Alarm volume: 70~85dB(30cm)10, maximum power: 2.5w Host 1. New trend of shell, ABS new material manufacturing.2. Dual CPU microcomputer intelligent control, from military technology, accurate and reliable.3. Patch motherboard, beautiful and neat, failure rate is less than 0.5%.4. Using imported chips, faster and more accurate.5. Residual vibration elimination technology to reduce false alarm rate.[Probe (Size: 22*20mm)]1. 22mm concave design, no water, unique design to prevent ultrasonic probe to the ground and false alarm.2. Ceramic crystal vibration, longer life.3. Anti-interference wire, not affected by the original car signal interference.4. Beer head design, easier to plug, long life.5. Optional waterproof wire, easy to install.6. The probe adopts embedded installation, multi-color configuration sensor delicate and compact.