H4 SL2 Pro LED Bulbs

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).

APPLICATION NOTICE: 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. Legal for off-road use in ATV, snowmobile, and off-road racing use. International legality varies by country.
Note: This usage regulation is not unique to Diode Dynamics bulbs. All LED bulbs from all brands, regardless of marketing claims, are prohibited from street use in halogen headlights in the USA. Click here to learn more.

SL2 Pro LED Bulb Overview

Diode Dynamics set the standard for LED bulbs in 2017, with the introduction of the SL1 LED. The SL1 was the first bulb engineered to provide a true increase in performance. After many years, and thanks to improvements in technology, we are excited to introduce its successor: the SL2 Pro! The new SL2 Pro LED has been carefully refined and improved with 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. Unlike a traditional LED chip, TST LEDs are designed with electrical connections on the top. This means the entire bottom surface of the LED can be dedicated to channeling thermal energy out and away from the LED. This lowers thermal resistance, allowing the SL2 Pro to run at higher power levels than traditional LED bulbs, while maintaining focus.

Optimized Optical Focus. Your vehicle's housings are designed to focus light. If the light source in the housing is out of focus, it doesn't matter how bright the bulb is - you won't have a focused hotspot of light to shine down the road where you need it. Instead, you'll have more glare, which lights up the foreground and makes it harder to see in the distance. The SL2 Pro LED bulb was engineered to focus light just like your original bulb, matching the original beam pattern while still providing an increase in total output. These days, some LED bulbs on the market use the smallest LEDs possible to accomplish focus, but this leads to "over-focus", where you begin seeing streaks, lines, and harsh cutoffs in the beam pattern. Instead of using the smallest LEDs possible, the SL2 Pro was optimized to provide a smooth and comfortable beam pattern, while still maintaining focus and increased output.

Internal Cooling. The SL2 Pro features an integrated top-mounted fan for superior thermal management and reliability. Since the fan is sealed inside the housing, there's no concerns about damage from dust or moisture over time. And with the fan on the top of the bulb, the cooling happens right next to the LEDs - the source of the heat. While standard LED bulbs use heat pipes and other tricks to move heat to the bottom of the bulb, where it's cooled off, the SL2 Pro keeps it simple and more efficient. This provides maximum cooling efficiency and output.

Fully Integrated Design. Unlike traditional LED bulbs, the SL2 Pro LED bulb doesn't have any extra wires or external drivers. Along with its compact size, that means excellent fitment inside your housing, without the need to tuck away wiring or bulky drivers. Installation is easy - simply remove your factory bulbs and the SL2 Pro will fit in its place, with a plug-and-play connector. For specific fitment information, please see Vehicle-Specific product listings, or contact us.

CANBUS Systems. Some vehicles use a CANBUS electrical system that can cause flickering or bulb-out warnings when LEDs are installed. These issues can be prevented with our Anti-Flicker Modules. Click here to determine if your vehicle needs Anti-Flicker modules.

Reliability. Every part of the SL2 Pro LED was engineered for reliability, from its full metal construction to the fully-sealed design. The SL2 Pro was put through its paces in our environmental testing chambers - where the bulb lasted through repeated thermal cycles from -40 through 85 degrees Celsius (-40 to 185F), along with a range of other environmental tests. It's also designed with transient protection, to prevent premature failure from electrical spikes in the vehicle. It's even compatible up to 30V! We're so confident in the SL2 Pro, that it's backed by an industry-leading limited LIFETIME warranty. See details at diodedynamics.com/warranty.