Originally Posted by 
BobD
				 
			I think the important thing is to get an Opticool windscreen, not that it is genuine. Even aftermarket they cost about double a plane glass windscreen. I have an alternative Opticool replacement and I find it is better than the original in that the cracks don't propagate in the same way. I now have three stone chips from my last three remote area trips and none have propagated. I have only repaired one because I was scared it would crack further but the other two are bigger and have not caused any problem.
I got one stone hit on my OEM screen near the bottom centre, and the crack went for most of the width of the screen horizontally and also vertically from the crack within a week.