These C-Light LED modules are circuit boards that fit right behind the factory diffusing reflector, illuminating in an extremely bright white, as well as a brilliant amber. Don't be fooled by other options on the market: these LEDs have been designed from the ground-up for this application, and manufactured in St. Louis, Missouri, to be absolutely the brightest lights physically possible. They are compatible with 2013-2017 Crosstrek Base model headlamps, not the WRX and STi headlamps.