Fog Lamp Puzzler

[palfy86]

So today ive bought two new fog lamps and i have a question a cannot seem to answer.

Right beside the normal mount holes theres like a long plastic threaded bar running down one side on the unit with a screwdriver head access in the top to adjust, but what does this actually adjust??

Any ideas guys?

 

[Broken Byzan]

the height of the beam by altering the angle of the reflector

 

[palfy86]

I thought it would be something like that. both my old ones are snapped (hence the replacements) ill be out tonight then when it eventually gets dark to adjust accordingly. Thanks for that