Light came on, Not sure what it is.

I just bought a used ML320 and I never got the owner's manual. I was hoping someone could help me with this problem. The light that came on is located on the dash and is in a form of a amber/yellow circle with 4 curved lines surrounding the circle. Any help would be appreciated. 

ITS SOUNDS LIKE THE LOW BRAKE PAD WARNING  light.

Thanks for the help myamg. Can anyone else confirm this?

It is the low brake pad warning light....mine just came on but only when I apply the brakes...I am sure when the brakes become worse the light stays on indefinetely!