The Men's Classic Thermal Merino Base Layer Bottoms are made from a heavy weight wool fabric which will help keep you warm and comfortable as you ski, run, hike and explore the great outdoors.100% Merino wool fabric made with an interlock knit - for enhanced comfort, breathability, thermoregulation, and odour resistanceFit updated to improve functionality while enhancing aestheticsMerino-covered elastic waistband and traditional fly designFlatlock seam construction - designed to minimize chafingSize M inseam: 30" (76 cm)Weight: 0.503 lbsFit: Slim