LED Elegance: The XTR C Series family isn't designed to hammer an insane amount of intensity out of your turn signals or brake lights. These are the most sensibly designed replacements for incandescent bulbs that are engineered to provide you with all the benefits of LED in a package that's built to last. Engineered: There is nothing else quite like the C Series in the world. They are molded entirely of ceramic, which we've selected for its resistance to thermal soak. The mounts for the optics are molded in, as is the LED driver and it's electrical circuitry. The Xenon Depot name and reputation aren't enough to justify the higher than average market price. It's justified by the exotic design and technically advanced construction. Optically: We've engineered with the conical reflectors to distribute light in an even radius to properly illuminate the reflectors in all turn signals, marker lights, brake, and back-up lights. The contrast ratio between low and high intensity modes is equivalent to the OE System to ensure that other traffic is fully aware of your intentions. Options: The 3157 XTR C series is available in red, amber, and white. They LED package has been carefully selected to produce the most appropriate CRI in their application. Family: The C Series family includes a full range of LED bulbs in all sizes. Because they're so unique, we recommend matching your selections from front-to back within the family to ensure consistent looks, performance, and functionality. These are the last LED bulbs you'll ever need to buy, so do it once and do it right with the XTR C Series. Hyperflash Like most LED bulbs on the market, the XTR C series consumes less power than the original bulbs and could trigger hyperflash if used in a signal application. We recommend installing the optional LED Load Resistors in those cases to re-balance your electrical system.