This item is actually really well built. You can see how much thought came into it. I really like the quick release switch on the strap and the fact you can adjust the cord to give more or less slack.
The cord comes with 5 markings that each represent 1lb of force, I was able to comfortably do manual labor outside at a few lbs of pressure for a few hours before taking it off during my lunch break.
This is a great device, much better than the cheap ones you get elsewhere