Size of the screen: 5.3cm(H) X 8.2cm (W) X 2cm(D) and visual size: 3.8cm X 5.9cm,A buzzer is built in the unit with switch for turn the sound on/off. it can be used for any Car, Estate, 4*4, Van, HGV's, Caravans, Trailers and Motorhomes etc. The buzzer sound in different frequency according to different distances. Details shown in the table: Specifications: 1. Wireless CPU to display communications, there are not any wire between the main board and the display. 2. Digital LED showing obstacle distance 3. Alarm by Bi-Bi sound 4. LED display with three colors (Red, yellow & green) 5. Crescent shape digital display screen 6. Turn on/off the voice according to your desire 7. High quality and easy to install. Technical Parameters: 1. Rated Voltage: 12V DC 2. Operating Range: 10.5V~ 16V DC 3. Rated Current: 50mA~ 180mA 4. Detecting Distance: 0.3~ 2.0m 5. Ultrasonic Frequency: 40KHz 6. HF Frequency: 315MHz / 433MHz 7. Display Working Temperature: -30 ~ +70? Kid includes: Wireless digital LED display with fused cigarette light plug. Centre control box with power cable to connect reversing light. 4 sensors, can be colour coated,sprayed and painted.