I bought the Progressive 440 in Rapid City, SD, I love them the are totally adjustable with your hand. They have a red dot to keep the sides in sync. My Bike would not bottom out but kept wanting to come up in the apex of the curve, which I thought was me but after a year and a half I was convinced it was mechanical. This shock took all that out and I can corner with the bike under me, even if I have to reduce speed. Very happy but they were not cheap $635. I am running at about 2¾ turns of preload. The nice thing about doing this at a company trailer you get a lot of info that you would not get in any other way, and they install them so they do the measuring etc.