WARNING: This page is about a different car, the 2009 Mercedes-Benz E350 and 2008 Mercedes-Benz E350. However, it is still accessible from the selected car via links, so may be relevant.
FG 63/Set K
MODEL 211, 219.3
Use:
Set of covers for protection of fuel tank from welding spatters when replacing outer right rear wheelhouse.
Fig 1: Identifying Set Of Covers (211 589 00 91 00)