This article gives an excellent overview of Blood Flow Restriction Therapy. It includes information regarding BFR Cuff width, material, and shape. It also gives rehabilitation guidelines, safety implications, the physiology behind muscle hypertrophy, etc.
Lastly, there are a few linked videos explaining and demonstrating Blood Flow Restriction and some excellent resources at the bottom of the page.
Read more here: https://www.physio-pedia.com/Blood_Flow_Restriction_Training