When things start heating up on the road, you'd better have a good pair of socks in hand. And you won't put a foot wrong with the brand new generation PRS Ultralight Run, designed for optimal thermoregulation when training and racing in hot conditions.The featherlight, technical mesh is designed to fit like a second skin. It offers exceptional ventilation and quickly wicks away sweat so your feet stay fresh and dry, even in tropical climates. The reviewed, wider toe box offers an ergonomic fit and improved proprioception, allowing the toes to expand intuitively on landing for a natural, fluid stride. A special knit around the ankle, lighter than our classic running sock, offers gentle support as you push the pace. Our characteristic arch support prevents the fabric from twisting and irritating in the heat, while a terry cloth reinforcement around the big toe saves you from blackened nails as the miles build up. Say goodbye to blisters! The signature 3D.Dots and new Flat.Dots on this ultralight model save on volume and weight but still provide high performance benefits. Running the length of the Achilles tendon, they offer added protection support and ventilation during fast races. Underfoot, a clever pattern comprising of 50% 3D.Dots and 50% Mesh.Dots cushions impact and adds grip in the shoe. It also provides gentle micro stimulation to increase venous return and enhances ventilation by increasing airflow between the dots. The sock height is lower than the trail and bike models to answer the demands of road running. An ergonomic tab at the back adds a touch of comfort and style and, should you forget why you're heading out the door, the discipline is discreetly embroidered on the inside. An explosive blend of technology in a weightless package, this 4th generation Ultralight running sock is your new weapon of choice to take on the Saharan desert or race a heat wave in Boston.