This 18 L.E.D. emergency flasher features a magnetic backing so it can be quickly attached to a bumper in the event of a breakdown or auto accident.  Great item for the back of trucks or trailers in case of light failure. The Flasher operates on 4 AA batteries (included) and will provide a constant or flashing red signal for 48 hours plus or a steady function for up to 10 hours.  Also comes with built in stand to set on floor  ( use in replacement for hazard triangles) . Great emergency safety light available. Up to 1 mile visibility.