I played with the helmet mirror the other night to see if I could actually see clearly behind me with the helmet on. I actually was able to see quite well and it looks as if though this will work better than the eyeglass mounted mirror that I had tried last year. I was hoping to get it permanently mounted on the helmet by this morning, but no luck. Did the charity ride without it. No close calls, but I was still a bit apprehensive when riding outside of the bike lanes and on the street. May get the mirror mounted today for tomorrow morning's club ride.