S3 Series H4 LED headlight conversion bulbs. Powered by Genuine Philips Luxeon LumiLEDs. Designed for use in automotive forward lighting systems, the brilliant cool white light from the Philips LED chips deliver powerful light output. Get up to 2 times the light output compared to most standard halogen bulbs! These powerful & efficient headlight LEDs provide you with excellent visibility. The S3 LED bulbs can be used for retrofitting nearly any Headlight or fog light that uses a H4 halogen bulb.