“My husband loves the vest. It's versatile enough he can wear it under a heavy coat when shoveling snow or on its own in a cooler office building. He said the placement of the battery pack is excellent because it is out of the way. He wears a size medium in almost everything, and the medium vest fit him perfectly so it is true to size. He's only had it for a few days so far, so I cannot comment as to longevity.”