If you are looking for a gas-discharge lamp, you may require D4S, depending on your unique requirements. These sources of light are exempted from the guideline on UN Regulation 37. Besides, they generate light and other forms of energy by emitting an electric discharge.
However, they can be road illegal. According to Regulation 99, you can use D4S strictly in your car’s headlamps. As such, before you head to the shop to buy one, ensure you restrict yourself to the right product.
D4S bulbs are mercury free. They are tailored for projector systems. For that matter, you can use them and then dispose of with ease at the right time. Remember that mercury is unfriendly to the environment.
The base of D4S is P32d-5. And, the bulbs consume 42 volts and deliver 35 watts. When you want to replace them, use the base-type to determine the right choice.
On the market, you will find D4S bulbs that use halogen, Xenon, LED, and much more. Whichever choice you go for, be sure it serves your lighting needs. You can upgrade most technologies. But note that LED and HID lamps are some of the most advanced options that savvy car owners are considering.