Here's how to take it. Need it in inches please:
1) Get a ruler, scissors, scotch tape, a pen and sheet of paper.
2) Do what you see the person in the above video doing. The strip of paper being cut is narrow, just 1/2 or 1/4 inch wide. He is using a small piece of scotch tape to secure the base of his trigger finger. Then, he's pulling the paper around his trigger and middle finger, where he wears rings. He's pulling the paper to "snug" but not tight. He marks the overlap point with a pen, and measures with a ruler.
After the final step, it looks like this: