Ultra-light construction + cushioning + Coolmax = the perfect warm weather running sock. Our Vertex Ultra-Light Cushion has the sleek feel of a super stripped down, lightweight running sock but delivers cushioning just along the bottom of the foot. Coolmax Polyester yarns move moisture away from your skin and are fast drying. True Seamless construction reduces hotspots and blisters. Ultra high stitch count creates a super comfortable sock with a streamlined fit like no other. Plus they even have that handy lil' tab on the back so they slip on easy. No slipping, no bunching, no blisters. Still made in Vermont. Guaranteed for life.