From the Lindner Quality Socks website -
Every great team needs an all rounder, and the 'Otto' ribbed sock is ours. The merino wool ensures it’s warm in winter and the ribbed style ventilates your feet in the summer months.
The 'Otto' is durable and works well with a wide variety of footwear, from sneakers, to riding boots to work boots, a true all rounder.
Fibre Composition: Merino Wool: 75% Nylon: 25%
Sizing information: The Otto sock is designed to be a crew length.
Small:Men's 4-6.5Women's 5-8.5Medium Men's 7-10.5Women's 9-12LargeMen's 11-14Photos and information from the Lindner Quality Socks website.