Knit caps in military service go all the way back to the Crimean War and perhaps earlier. Their civilian popularity began in the 1940s after the Second World War. They were very common with naval crews in the northern oceans and submarine crews in the depths. Their lightweight construction made them easy to shove in a pocket when not needed and their length allowed them to be pulled low over the ears. This is the modern spin on that timeless classic.
The U.S. Military started messing around with synthetics in the 1990s and just went nuts with it. Eventually almost everything was polyester or somesuch. These hats are made from PolarTec Fleece, which is crazy warm and crazy light. They'll last forever, and are one size fits all.
These watch caps are available in black, coyote, and foliage.
Oh yeah, these are 100% made in America by Americans. Not imported.