CW-X Women's Endurance Run Vest 80% Polyester/20% Polyurethane Imported Flexible, lightweight soft shell stretch polyester fabric. Water Repellent. Wind resistant Breathable stretch polyester/spandex panels in the back shoulders for comfort flex Under arm mesh panels for ventilation Drop-tail back with lower lumbar zipper pocket with reflective tape YKK flip lock zippers and reflective front logo