Small From Columbia website: OMNI-HEAT: Our patented Heat Reflective garments are the ultimate body heat management system for outdoor performance. The interior lining consists of our metallic dot pattern designed to retain heat, while the breathable fabric dissipates moisture. OMNI-TECH: This proprietary technology provides air-permeable protection that's waterproof and breathable, keeping mother nature's elements out, at the same time allowing the inside to breathe, keeping you dry and comfortable no matter the conditions. COMFORTABLE WINTER JACKET: The Columbia Men's Whirlibird IV Interchange Jacket is the perfect multiple-use winter coat. The zip-in interchange system is easy to configure for different winter weather conditions. CLASSIC THREE-IN-ONE DESIGN: This men's winter coat is the classic 3-in-1 solution. Featuring a waterproof outer shell and an inner windbreaker jacket, with its own Thermarator insulation, that can be worn separately or together for maximum protection. WATERPROOF AND BREATHABLE WINTER COAT: Made with advanced technology materials including reflective elements, a removable and adjustable hood, and critically seam-sealed, this men's winter jacket will keep you incredibly comfortable and