What is this

[M T Pockets 000]

What is this and what is it for?
2011 Polaris 500 HO Sportsman. Discovered this dial on the right side of the speedo cover. It moves up and down.
Inquiring minds are ???

 

[gtk]

cant tell much from pic, but just guessin it could be headlight adjuster (up/down)

 

[M T Pockets 000]

Hummm...... Hadn't thought of that