ASR Switch for Traction Control Genuine Mercedes C107 this rebuilt switch has been Electrical Parts this rebuilt switch has been refurbished with brand new components at all of the common fail points A genuine OEM Mercedes Front Bumper Tow Hook Trim Piece for Mercedes R129 model vehicles it allows the driver to manually toggle or temporarily disable the vehicle's traction control for enhanced wheel traction in conditions such as deep snow or when utilizing tire chains It is most commonly found on the W140 C140 S Class sedans and coupes (such as the S500 and S600) as well as the R129 SL Class roadsters (including the SL500 and SL600)