The WRIGHTSOCK Double Layer CoolMax® Quarter Sock is highly recommended by many marathon runners and triathletes that demand a sock to help prevent blistering under extreme situations! This sock does just that. The construction of lightweight CoolMax does not compromise the fit of the shoe while still allowing two layers of material to absorb the friction with the slight movement between the layers. Feet stay dry as the CoolMax wicks the moisture away from the foot and into the outer layer for evaporation. Many people use this product for a variety of activities in addition to running. WRIGHTSOCK will donate a portion of the proceeds from the sale of this product to Breast Cancer Research. So whether you are training for a fundraising walk or just want to show your support for this cause, you can keep your feet comfortable at the same time!