I got the foot warmer today and my first impression after a few hours use: Finally at work on the PC cold feet !!! - In the past few weeks with me "frostbite" superimposed also two pairs of socks and sheepskin shoes does nothing more - had nevertheless always cold feet.
They make you feel as a man a bit funny to, when you have so are a thing under the desk. But the end justifies the means in this case.
The product makes a very well-made impression and what I especially like that the heated area surrounds the toes well - so there very well warmed, where cold feet are particularly unpleasant.
With shoes, one should not use the product - as the removable inner lining suffers probably quite fast. Otherwise, it is also for me with shoes size 44 quite "spacious".
Buy recommendation!