I don't doubt that the handle is more ergonomic than grabbing a metallic cylinder; but I think in the depicted use cases, you'd already have a light-casting device of some sort. That being said I'm not a recreational outdoorsperson; if you are, does this seem useful?
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In any case, it's designed to fit 30-oz. tumblers, but can be stopped down to a fit a 20-oz with the included adapter. Runs $30.
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