A short off road ride and a flicked-up stone can mean the premature end for the expensive head lamp glass. When riding with a group, a lot of stones are thrown up by the knobby off road tires of the bike in front. These are potential lamp killers.
Important note: The protection grill cannot be folded away, this means that in some countries they are NOT road legal. Please check and use only for off-road in these cases.