Quick-start voltage stabilization design, instantly light up the headlights with stable brightness and no flicker, improve driving safety Waterproof and shockproof high temperature resistant structure, adapt to complex road conditions and bad weather, longer service life 8X0907472 8X0907472A Headlight LED Control Unit Daytime Running Light Module Ballast for A1 2011 2012 2013 2014 Function: The headlight ballast regulates current and voltage to ensure that the HID bulb can quickly and stably reach its operating brightness, while preventing bulb damage due to overheating or overvoltage [Installation]: No modification required, direct replacement. Standard fasteners are used, and installation can be completed in minutes with simple tools, Manufacturer: JIIYP