Size Large Color Optifade Waterfowl Marsh From the manufacturer: The Grinder Half-Zip offers a breathable yet insulated layer to wear throughout waterfowl season. Made from a blend between polyester and elastane, the SITKA Grinder Half-Zip offers plenty of stretch for a greater range of motion, while the waterproof and windproof technology keeps you dry and warm. The Polygeine® Odor Control Technology treatment neutralizes odor from sweat to keep you scent-free and undetected. Plus, the half-zip closure provides versatile ventilation and breathability when temperatures start to warm up.