THERMADENIM THERMAL SKINNYTHE BRUSHED FIBERS IN THE FABRIC TRAP WARM AIR FOR INSULATION AND HELPS KEEP YOU WARM DURING THE COLDER SEASONS!THE FABRIC ALSO HAS 4-WAY STRETCH WHICH ALLOWS FOR MORE DYNAMIC MOVEMENT & COMFORT WHEN WORN.58% COTTON 29% POLYESTER (23%VOLCANIC FIBER) 10% ACRYLIC 3% SPANDEXRISE: 10"INSEAM: 28"