I have 2011 FE390 with radiator guards, I bought bike used with these on so I don't know if they are stock or not. I believe these are Husaberg guards, they are black plastic fins. The idea is I guess the air hits the inside of the tank cowlings and push the air in thru the fins. However it seems to me the fins aren't very wide open. Has anyone ever tested temps with guards and without. We all know these bikes tend to run hot