He must have been doing it himself

[dennis]

Maybe he should have used a fitbit?

[John Rumm]

Don't they pinch?

[dennis]

They might if you tighten them after fitting. I was thinking of the velcro ones at the time. Maybe you were thinking of the metal fold over ones?

[NY]

Does "clot" describe the congealed blood or the person who uses the ring - or both? :-)

[John Rumm]

Just the normal zip tie nylon type...

[whisky-dave]

Hose clamps would work too. Even heat shrink sleeving to get a snug fit and a choice of colours what more could you ask for.