Only small area of velcro, doesnt feel strong but works. Comfortable fit. I'm an AU-size 12 and the large is perfect for me. I like the separate key zip pocket as you dont lose or drop your key when you get your phone out (my experience with single pocket belts).
***7 month update*** In the bin now, elastic worn and stretched out, can no longer tighten for a secure fit. Used about twice a week