By reversing the rubber tube on the back and reclipping the adjusting screw in the mirrored position it will fit the the other fog lamp. The actual mirrowed part is identical for both sides of the car, as are the rubber tube, the adjusting screw and the O-ring. Only the housing is mirrowed for left and right hand.
The hole in the front of the lens goes at the top of the housing and the rubber tube is a breather which comes from the back of the hole and points down. The adjusting screw is on the opposite side to the rubber tube position. The bulb is positioned so that the bulb connector points down.

The part shown in the photos is the second generation unit which dropped the built in reflector which often came loose.
If the reflector falls off it can be hidden from sight and the method to do this is outlined in a PDF by 04Fire CLICK on this forum.