D2S / D2R plug adapters are needed in order to use D2S or D2R bulbs for your new HID projectors, and still use your aftermarket HID kit! These particular plug adapters are the best on the market! You can't compare the sturdiness of them as well as the weight too! Take a look at the weight difference! If you don't think .4 oz is allot, take a look as to how much .4 oz is.