hello roo...it is a braided loop made from dacron...it is whipp finished on the shank...it is a traditional way done long ago by anglers from 1700-1900...in those times in Ireland and Scotland there was some concerns about the strength of the steel hooks...and they fashioned their loops from "gut"... double hooks were exactly that I understand...and the lashing held them together too...
I just like to do it old school sometimes on the salmon and steelhead ties...
its plenty strong...and has some flexibility qualities that are pretty interseting as well...the loop goes back on the hook almost to the curve, double on both sides...its just lashed or whipped with tying floss and tied off...
you can see it pretty good in this picture...
I am by no means an expert in the style of tying classics...just a student...but the history of angling is really pretty cool...t