These men's thermal underpants keeps pleasantly warm while being very breathable. The best combination for winter! Details: Fast-drying, odour-inhibiting NATEX material, Breathable COOLVENT ventilation, HEATMEMORY technology keeps you warm during breaks, Warm DURAFIT panels on knees, Moisture-wicking DRYLIGHT technology on back of knees and lower back, Seamless FEELINES design.