WHOLESALE BATTERY OPPERATED MAGNETIC TRAILER LIGHT Emergency Flasher With Magnetic Base. Uses 4x AA Size Batteries (Not Included). Simply Insert Batteries, Press the "ON" Switch and Set Unit On Metal Surface To Warn Drivers Or Attract Attention. Brilliant Bulbs Present A Beacon Of Light Visible For Up To One Mile. Fully Portable, Needing No Wires Or Connecting Hardware. Heavy Duty Magnetic With More Than 50 Pounds Of Holding Force. Uses 4xAA Batteries (not included) Provide Power, Eliminating The Need For External Power Sources Or Wiring. Portable Design Is Perfect For Towing, Security, Emergency Lighting, Or Anywhere Extra Light Is Needed. Durable,Weather Resistant Case.