One of the easiest ways to put a dent in your ride is simply by backing up or trying to parallel park. But a new collision warning system is trying to make it easier to know what’s directly behind you when you drive. FenSens Fender Defender is a two-part system that connects a car’s rear license plate to its driver’s smartphone and alerts him or her to any pending obstructions.

FenSens’s special license plate cover features four ultrasonic sensors that can detect what’s happening about 10 feet behind your car. Users only have to screw the cover on, then download the smartphone app, which connects to the license plate cover via Bluetooth. FenSens Fender Defender can then give you ample warning if you’re in danger of hitting something, with a series of beeps or vibration alerts (just in case you forget to take your mobile device out of your pocket). The app also uses your smartphone’s display to give you a view (albeit a minimal one) of how far away you are from objects behind you. The license plate cover is both waterproof and dustproof and has its own battery, which needs to be recharged about once every five months.

FenSens Fender Defender is iOS and Android compatible and available for pre-order for $150 with a $99 early bird special if you sign up now.

[h/t Gizmodo]