Polypropylene is not a dyed fabric. The color is built into the fabric so you won't have any bleeding or fading. Polypro keeps feet warm and dry. Polypropylene is a synthetic fabric that does not absorb any water making it hydrophobic. The fabric speads water evenly across the feet allowing the fabric to dry quickly.
The Black sock is manufactured for the military. It says it fits mens sizes 10-13, but it will easily fit down to a Men' size 8.
Coldpruf Thermal Base Layer