OEM Detroit / Mercedes Temperature Sensor A6804900337. For Aftertreatment Systems This is not an aftermarket part, it is OEM. These units are OEM "take-offs", they are brand new and unused but do not come in Cummins retail packaging. We buy complete units from Cummins and then break them down so that we can sell the pieces individually. Due to this, there may be paint marks or minor cosmetic blemishes, but we assure you they are brand new and genuine.