I've had a Givi 601 on my Speedmaster for over a year.
Quality is tops. The 601 is 16.7x14.5 and the 620 looks to be 19.5x20. I had no problem mounting on the bars. The smoke color is not that dark. As for turn sig. clearance might be time to cut a piece of cardboard the size of the shield to get some idea as to the fit. I had to do a bit of adjusting to reduce the buffeting. Good luck, you wont be sorry going with the Givi.
Mark
