I'm buying these as a gift. If you're not sure, buy a medium for a woman and large for a man. For children, buy a small. If they don't fit you can return them within 30 days for an exchange or refund. Yes, your hearing is not affected.
Most people think so.
They are not elastic, so there is no constant pressure on your ear. Ear Pops are made of Polarfleece, manufactured by Malden Mills, which is the same material used in fleece parkas, jackets and vests. They provide excellent insulation from the cold. I measured my ear and it's on the border between a medium and a large. If you're between sizes, go up in size.