It folds very compactly. A more elaborate one is made of metal gauze.
If you smoke get a head net provided with an opening for the purpose.
Gloves
A pair of light leather gloves is a comfort on " nippy " days and also protects one from mosquitoes. For the latter purpose tackle dealers sell a thin gauntlet that covers the entire forearm.
Goggles
Some anglers find the sunbeams dancing on the riffles very trying to the eyes, making a pair of green or amber-colored goggles very comfortable. They cost from fifty cents up.