In reply to chris_B:
Yep, I have the Lenz ones. Really good.
There's 2 battery options - well worth getting the better batteries IMO.
They last 6 hours on low setting but you don't feel 'warm' you just don't get cold feet.
On high (lasts about an hour) they actually feel warm.
Be careful not to lose a battery, I never have but mates have. I might tie some cord on to mine for this winter.
I use mine primarily for alpinism.
Tip is to wear a very thin liner underneath, so you don't have to wash them as often. They get smelly easily otherwise.
I've washed mine on 30degrees as per the instructions with no issues, but it can't be good for them in the long term.
Hope that helps!
Cheers,
Jack
