Get your semi truck Ready for the Road Ahead with steady flash rates for lights, with the OTR 2-Prong 20-Lamp Electro-Mechanical Flasher. This replacement device sets a consistent flash rate for lights, creating a controlled pattern that can be seen by other vehicles or pedestrians. Engineered with a versatile design to be suitable for everyday driving, alarms, or hazardous situations. FleetPride is your First Click in Heavy Duty .