Overview Added function. This harness was designed for use with Diode Dynamics 2015-2021 Subaru WRX/STi C-Light Switchback LED Boards ONLY. This harness allows your C-Lights to also function as the daytime running light. It will deactivate the factory daytime running light, and instead power the C-Light. Your high beam function will still work as normal. Easy Installation. Using OEM connectors, this kit is 100% plug-and-play and installs in minutes. Reliable Operation. This module has been designed with quality components, custom-tooled OEM-grade connectors, and includes embedded circuit protection, for high reliability over time. It is proudly assembled in St. Louis, Missouri by Diode Dynamics Manufacturing. Experience. After over a decade in business, Diode Dynamics is the most trusted name in automotive LED lighting. Unlike every other LED distributor, we assemble and engineer products ourselves in the United States, for high quality and fast time-to-market of the newest and brightest LED technologies. We pride ourselves in offering only quality LED products, that will exceed your expectations. Please contact us if you'd like to discuss your lighting project!