Ive bought 3 sets of thumb rings from custom thumb rings, once by measuring and twice by using their thumb ring sizing tool. One that i had that fit broke, i think due to the engravings in it. Now im left with only one ring that fits as my thumb has gotten too big for anything else. After watching this i will measure my thumb this way and order my next from vermil. Their rings look much sturdier. Your shooting method and explanation of back tension has also greatly helped my shooting.
I used epoxy to secure the leather lining (the HIT epoxy used for gluing Easton inserts into shafts, but it could another flexible epoxy). The leather lining goes by "pichen" or 皮襯 in Chinese. It goes by "kulak" in Turkish.
