The Smartwool Microweight beanie, if you couldn't tell from the name, is ultra lightweight. This is good for when you don't want to feel like you have weights on your head. Or when you're trying to pack all your stuff and you don't want to go ONE OUNCE over your weight limit. This Smartwool beanie will help with that. It also protects your head from the sun. Anyone who's ever had a sunburn where they part their hair knows how important that is.