They are ok for using on your ankles.
I actually purchased these to use on my wrists while walking. However, they don't tighten up enough to use them around my wrists. So, if you have small wrists they aren't good to wear. I could use them, but they would be sliding around on my wrists as I walked. However, I can't stand things moving around on my arms or legs. So, they didn't quite work for what I used them for. My sons use them as ankle weights though and they work fine that way.