What a surprise---
Is a fabulous coat for cold days to be outside.
A great product!
There are a lot of cold and very windy days here on our ski slopes, that would occasionally force me to quit before I was tired, but not any more! If I quit early, its not because Im cold, but Ive worn myself out (Im only 69, and still going strong). The vest that this battery goes in makes a cold, snowy, windy day seem like a lovely spring day. I purchased a second battery, more as a back-up, but have never had to change batteries during a long cold day. Its a must have.