All of my measurements say there were no changes in the hard parts except maybe the groove depth they did apparently go with a slightly larger size for the o ring so I have to concur with the 101 size and will order some to see how the go into the older size ring.Not hard at all. I think the original o-rings are larger than 101mm in ID as I had to pack more of the extra slack into the grove. Also, the original orings are harder to don off. I ran a few tests in the Lakes and will post a more detailed response when I am back home.