Features Advanced TST LED Technology for industry-leading performance.Internal cooling for superior reliability.Fully integrated design no wires or external drivers.Direct replacement bulb with compact fitment. Backed by limited lifetime warranty. Designed and engineered in USA (Patents Pending). Introducing the SL2 Pro LED Bulb! As a replacement for the popular SL1 LED bulb the new SL2 Pro LED features some major upgrades: next-generation TST LED technology an integrated top-mount fan and a fully-integrated wire-free design. As a direct plug-and-play replacement it provides a significant increase in output in a compact package. Next-Generation TST Technology. The SL2 Pro features new thermal separation technology (TST) LEDs. TST LEDs are designed with electrical connections on the top which lowers thermal resistance allowing the SL2 Pro to run at higher power levels than traditional LED bulbs while maintaining focus.Correct Optical Focus. The SL2 Pro LED bulb was engineered to focus light just like your original bulb matching the original beam pattern while providing an increase in total output. Instead of using the smallest LEDs possible which can lead to streaks lines and harsh cutoffs the SL2 Pro was optimized to provide a smooth beam pattern while maintaining focus. Internal Cooling. The SL2 Pro features an integrated top-mounted fan which provides maximum cooling efficiency superior thermal management and long-term reliability. Since the fan is sealed inside the housing there's no concerns about damage from dust or moisture over time. NOTE: LED bulbs are legal in the USA for Fog Light use only. Not compliant with DOT / FMVSS108 and not street legal in the USA for Headlights. International legality varies by country.