Sylvania Linear Double halogen light bulbs have a two ended base. This means that at both ends of the bulb, a base is attached. This is called an R7s base. With the filters on the right, you can choose the wattage and light color you desire. We advise you to keep the same specifications as your current light source if you want to keep the same light effect. Make sure you choose the right length! Did you know that there are also LED R7s light sources?