I think these were really meant for the grips I have on the Goldwing. These are more for touring type grips with the Chrome end and the Chrome sleeve. I was really looking for just some foam slip-ons for my gf gw250. But anyway. I'm not complaining. I just cut them to fit and they slipped right on the gw250.
Wanted something to reduce vibrations and take some of the stress off my hands. Definitely works for me. Mine slid on fairly easily (wetted it first), and tried to go slow and not tug too hard to avoid ripping them.
Had to trim about an inch which was easy with sharp scissors. Only used them for a few weeks but they appear to be good quality neoprene so should last a few years.