Mount Collision Sentry warning system in critical areas of your facility to lessen accidents at blind corners. Vehicle collision avoidance system detects motion on both sides of "blind corner" areas then provides both visual and audio warnings to alert people of approaching traffic. Detection zone is 20 to 25 feet from both sides of the corner. Built-in magnets on the back enable hassle-free installation to metallic surfaces or use Collision Sentry Z Clips for non-magnetic surfaces (sold separately). Highly visible compact Collision Sentry device is self-powered.