Jake,
Those loops are made by New England I think, I talked to the head of the company about them. They sell to Harken and others. It is Dyneema SK-75 spliced in a loop/hoop like Brion shows in his book 5. They have a nice looking cover over it. Harken as well as many others are going to looped blocks. It all came out of the big round world race boats who were lashing blocks vs. shackles.
I just up loaded a bunch of photos to my URL and one shows the use of a softie on a boom block on the Westsail.......we renamed it the "Wireless Westsail"...check it out.
