XKTTSUEERCRR 54LED & 18LED Vehicle Windshield Dash Deck Grille Strobe Flash Emergency Warning Strobe Light Bar For Truck, Law Enforcement, Police, Firefighter, EMS, Ambulance, Private Security (Blue) *One set suitable for windshield/headliner placement and the other suitable for grille placement(See product images). *Easy to install, Just need to wire the positive ( + ) and ground ( - ) to a 12V power source and connect each LED bar to the controller. *High Quality, Professional Grade products, weatherproof and long lifespan over 50,000 hours. *Suitable for emergency workers, postal service, construction vehicle,security, law enforcement, hazard warning, towing, and emergency needs, etc. *There are 3 flashing modes: A:Flash one kind of color 8 times and switches off to the other; B:Flash one kind of color once and cycle between the two; C:All LEDs flash several times.