It's lightly cushioned, it's durable, it hugs and protects your foot from beginning to end of whatever heart pounding activity you decide to indulge in today. The Pulse is Darn Tough's ultimate endurance sock. Fine gauge knitting makes this a fast drying and breathable all-weather, all-activity sock that stays cool in the summer and warm in the winter so you can keep going and going and going. And as always, Darn Tough backs up its tough promise with an unconditional lifetime guarantee.