A DeFeet favorite, the Woolie Boolie is padded throughout the footbed and on the cuff, keeping you warm in any season without getting too hot in mild weather. Contents feature a blend of USA Merino Wool and Repreve, a recycled performance fiber locally manufactured from recycled plastic bottles, reducing landfill waste. Wool pulls moisture away from the body, keeping feet warm and dry in all kinds of weather. As a thicker sock, the Woolie Boolie has a mid-density padded fit profile for the rigors of mountain biking and endurance for hiking.