If you're looking for a lightweight layer that is also provides wind and weather proof protection, look no further than Smartwool's PhD(R) Ultra Light Sport Vest. The added benefit of body mapped panels of PhD(R) Ultra Light Mesh provides the ultimate in breathability and temperature control. Shell: 100% Nylon. Trim: 54% Merino Wool, 46% Polyester. Body-mapped mesh panels for additional breathability and moisture management. Regular Fit. Super-light shell fabric with DWR coating provides wind and weather protection. Packs completely into chest pocket for easy storage. Garment Weight: 112 g = 4 oz. Imported.