The Guardian Alert™ Backup Warning System is a discriminating multi-phase driver aid that uses patented microwave-radar technology to detect obstacles behind a vehicle. Unlike other backup warning systems, the Guardian Alert™ Backup Warning System is so advanced it works in all weather and light conditions, sounds and audible alarm and triggers a visual warning in the driver’s compartment, only in the event of a problem, and is virtually maintenance free. FEATURES Dual alarm system alerts drivers audibly and visually with 3 LED lights. Ruggedly housed in steel reinforced, waterproof casings. 3 Standard detection zones at 3 feet - 5 feet - 9 feet or 3 feet - 6 feet 12 feet (factory adjustable). Detection range covers entire width of vehicle. BENEFITS Works in all weather & light conditions. Senses through dirt, ice, snow, fog etc. Maintenance free. Active only when vehicle is placed in reverse–eliminates annoying false alarms. Installs in less than 30 minutes with no special tools required.