It is an w211 E-class equipped with a smaller version of the m272 petrol V6. Wasn't sold in the USA, but common elsewhere.

The m272 family has a significant issue which you should investigate before purchasing. Like all 90 degree V6 engines, it uses a balance shaft for smooth running. The shaft is driven by the cam chain. The problem is the manufacturer did not appropriately harden the drive teeth on the shaft, and they frequently wear down over time. The first symptom is a MIL light with OBD codes indicating that camshaft timing is off - due to chain slack caused by the worn teeth. The repair is expensive, about $4500 US.

The affected engine number range is published, you should be able to google it up. So find the engine number of the car you are interested in and make sure it is either outside the affected range, or has already been repaired.

Other than that, it's a good car, albeit 10 years old. Give it a good prepurchase inspection.