Aroma Season Heated Ear Warmer, Ear Muffs for Winter Women & Men Band Adjustable

How long does a full charge last ?

Is there supposed to be a strong odor upon opening the box? if so, what is the scent because i can't place it, but it's very strong.

are there instructions & product info to download somewhere?

Hi. Has anyone figured out how to adjust the size of these? I just purchased them and love them, but they are a bit too big for my head.