This sock delivers the trifecta for warm weather running. One: it's ultra-light beyond compare. Two: it still delivers the perfect amount of cushioning along the bottom of the foot. Three: Coolmax Polyester yarns move moisture away from your skin and deliver fast drying comfort. 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. Guaranteed for life.