We could be wrong here: but the 2014 Sierra was GM's first truck with an optional LED Daytime running light up front. Super modern for the time, but in a world where new pick-up trucks get a face lift every 2-3 years! By today's standards the design is getting a little old! which is ironic since GMC was still making the HD version of this truck through the 2019 model year. Time for a facelift! SEQUENTIAL LED DRL: The design of the Morimoto XB LED heads for the Sierra was inspired by look of the 16 through 18 Sierra headlights with the full C-shaped LED Daytime running light and honestly! if you didn't know any better, these things could pass for OEM! but it gets a bit better.The LED daytime running light is powered by Osram 5000K LEDs and is insanely bright, easily visible during the day! That daytime running light will also dim down when the parking lights or low beams are on for compliance reasons. Just below that: The trademark sequential turn signal that we've grown to love on so many of the other models in the Morimoto lineup. If you're not a fan of the sequential effect, no problem. You can run the blinker in standard mode too. All wrapped upside a gloss black housing, these things would be a killer aesthetic upgrade for any truck! . But the real beauty here is that it's not ALLLLL about looks. These things are quite functional too. PERFORMANCE: Sure, your truck has projector headlights from the factory! . But take it from us, the projectors found inside the stock housings are bottom of the barrel performance-wise. Even with a set of good LED bulbs or an HID kit, its OK at best. For years, Sierra owners have been doing projector retrofits with higher performance units just because that's the only real way to fix the Achilles heel inside these housings. But: if you don't want to mess with all that, the Morimoto XB LED headlights come standard with a high-output Bi-LED projector. Thanks to their advanced, modern optics and a 3in optically clear lens, they're going to perform even better than they look. The full LED low and high beam are an instant upgrade over stock, with a wider, brighter low beam, and a high beam that will penetrate far into the distance with ease. To top it all off, these optics meet & exceed all SAE, DOT standards when aimed properly, which is easy to do with their integrated aiming adjusters. PLUG-N-PLAY: As for wiring: Morimoto's LED headlights are designed to work on your Sierra without any modifications. They are plug n play on trucks that came stock with and without the integrated LED daytime running lights. No error codes! no flickering. No hyper-flashing! no nonsense. WELL-BUILT: Their UV-coated polycarbonate lens will resist the test of time, ensuring your truck's new headlights will look good as new for many years to come. The PPS plastic housing is light-weight and much stronger than comparable alternatives. The die-cast aluminum heat-sinks inside the housings provide more than an adequate amount of cooling for the OEM grade LED chips that produce the light. Let's face it: in 2019 GMC designers fell off the deep end with the new front end. If you've got a 14-15 Sierra 1500, or a 15-19 Sierra HD and you're looking to maximize the modern appeal of your truck with the last great front-end style GMC produced! there's no better way to do it. They've got the style. They've got the performance. The quality, and of course, they come backed by the best people in the business here.