Brand New Directed DEI 509U Ultrasonic Sensor Car Alarm Security New DEI XpressKit 509U Key Features Ultrasonic Sensor for Security Systems Detects air pressure changes in the cabin of the vehicle Adds extra protection when used in conjunction with other security systems Detect thieves entering vehicle without glass breakage Effective only when all entrances are secured and closed (doors, windows, and sunroof) NOT RECOMMENDED FOR CONVERTIBLE VEHICLES Dimensions: 4.5"L x 5.3"W x 2"H

The 509U Ultrasonic sensor is used to provide coverage of a vehicle's interior cabin area. The sensors detect movement inside the vehicle by sensing air disturbance. They should trigger the alarm if a thief has gained access to the interior of your vehicle. Physical Characteristics Height: 2" Width: 5.3" Depth: 4.5" Weight (Approximate): 8 oz Miscellaneous Package Contents: 509U Ultrasonic Sensor Mounting Hardware Wiring Interface Harness 2 x Ultrasonic Transducers