6x6- I have had over 40 w/s on my bike as to I manufacture them, my ride is like a swimsuit model and rd platform. There are many things that come into play when looking for the best w/s. Lower fairings windshield height, rider height, helmet or not and a couple of others. I make cut through or louvered ones that make the vortex of wind change dramatically for the rider- although some don't like because they think water and bugs come through. This may be true, but I road tested one of my "cut thru's" last aug in 95 degree heat for almost a 1000 miles and never caught a bug and rain wasn't any issue. My most popular 10" clear lexan is .125 and sits below most line of site and looks good engraved with or without light asssm. If you would like one let me know, I know many guys like the curved ones, they don't seem to make that much diff to me as the vortex spins around behind the window anyway, its really more affected by leg position, lower fairing or not and helmet on or off and type.