The CANbus Anti-Flicker modules are plug and play error free attachments for vehicle's who require this item for proper LED use. Not all vehicles need this. When searching for your vehicle on our website, if the Anti-Flicker modules shows up in any section (low beam, high beam or fog light), it is required. It can prevent multiple and different issues on different vehicles. Mainly, they enable daytime running light use with an LED conversion kit bulb.