The ROSS uses microwave sensing and can see through snow, mud, ice even a plastic bumper. Other detection technologies require an external transducer and they cannot be placed behind or covered by any type of material. Their performance can be seriously affected by the weather. The ROSS uses technology that is not affected by these conditions. You will hear a beeping sound which increases in intensity the closer you get to the obstacle or you can use the visual LED strip located in the rear window which changes color according to distance. (Green - Far, Red - Close).