This sock is available with either USA Merino wool or a blend of Merino and Repreve®, a recycled performance fiber locally manufactured from recycled plastic bottles, reducing landfill waste. Wool has naturally antibacterial properties, so it takes a lot of sweaty abuse to make a Woolie Boolie stink. Wool also 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. Thickest DeFeet sock; less compression than the Wooleator.