Aclima WarmWool Shorts Long with Windstopper for men are flexible and warm merino underpants. The fit is snug and the pants are knee-length. The front has a windproof material; perfect for training and activities requiring slightly more wind protection. Elastic waist is lined with wool for best comfort. Flat seams minimise the risk for irritation and chafing. WarmWool is a knitted material and thus elastic and flexible. The windproof material is less-elastic, so you may want to take a larger size than normally. Weight 130 g (size M) MaterialsWool fabric: 100% merino Waist band: 96% merino, 4% elastane Windwool: 100% merino with polyurethane coating Fabric weight, merino: 200 g /m² (19,5 microns)