Warning police lightbar

Normally,Some emergency vehicles use signs made up of a large number of light sources (usually LEDs), which can be programmed to display messages to other road users. This can be used to request other vehicles to pull over, indicate a special instruction, or just to display the name of the operating service (e.g. ‘Police’)–Yes,this is the Warning police lightbar,Led light bars.The warning lightbars can be used for many vehicles,such as Ambulance,Police cars,Fire trucks and Patrol vehicles etc.Often they are used along with a sirens in order to increase their effectiveness,because siren can control the lightbar’s flash patterns and the sounds of speakers.