Sylvania Britespot light bulbs are equipped with a GX10 base, making them very easy to install in your existing fixtures. These high pressure gas discharge lamps have a reflector through which the light can be spread in any desired direction. The HID bulbs have a longer lifespan of 6.000 hours, which saves you time and replacement costs. The light bulbs only work with an electronic ballast. Therefore, be careful when choosing another wattage. The ballast is adjusted to this. The Sylvania Britespot bulbs are not dimmable.