Implementation of the FEM on the calibration carriage stage at the entrance of CRIRES. In the left drawing, existing CRIRES components are labelled in black, while the FEM is labelled in red. The inset in the top left shows the inside of the FEM. The output ferrule of the FB is inserted vertically from the top in the ferrule support. The picture on the right shows the FEM after its installation in CRIRES. The FB (black-coated with a white sticker) is visible over the FEM.