CAR CRAFT Headlight Ballast Module Compatible With Mercedes A Class W176 B Class W246 C Class W204 Cla W177 Gla W156 Ml Gl Gle Gls W166 Slk R172 Headlight Ballast Module 1669002800 CC-1845Color: BLACK Features: Compatible With Mercedes A Class W176 B Class W246 C Class W204 Cla W177 Gla W156 Ml Gl Gle Gls W166 Slk R172 The Headlight Ballast Is Important As It Helps In Starting The Lamp And It Also Allows The Electricity To Flow Through The Whole Bulb Which Keeps The Lights On. It's Another Important Function Is To Control The Electric Current Flowing Through The Bulb. Premium Quality & Easy Installation: Made In Quality Materials, And