Designed for comfort and function.
 
43%Alpaca 43%Acrylic 14%Nylon&Elastic

Alpaca lets your feet naturally aspirate keeping them comfortable and therefore suppresses odor.
 
S - W 5-8 M 4-7
M - W 8-10 M 7-9
L - W 10-12 M 9-11
XL - M 11-14
 
All socks last longer when hand washed and dried but these can go in any gentle cycle.  Air Dry.