This sensor is the same like the sensors from Bosch or Metzger. The part is brand new, complete with o-ring gasket, only difference is the black rubber seal, bosch used red onces.
OEM reference numbers:
Mercedes: 006 542 77 17
Bosch:0280130044
Metzger: 0905333 / 0905420
This sensor is often used on the Mercedes 190E Models (W201 Series) and the Mercedes-Benz 200 serie (W124) and many more.
When a car has cold start problems, not running good when cold or hot, often this sensors cause those problems because its sent the wrong temperature to the ECU