My hands are always freezing and thought this would be a great idea.
They are exposed to the air and within half an hour become nice and hot and last for about 10 hours.
A brilliant concept however I found them too small as they only cover a small portion of a hand.
I bought these on special at Coles, Inglewood (WA) for $1.60 a pack of two.
Summary
A great product, however should be at least double the size.
#Kobayashi Healthcare
#Hand warmers