Icebreaker's warmest and most sustainable layers: not only is it a form-fitting, feminine and lightweight puffer, the Women's Helix Long Sleeve Zip is made with repurposed and highly insulating MerinoLoft , giving plenty of warmth with minimal bulk. A recycled polyester exterior is durable and water-resistant, fending off light precipitation, while a wool lining maximizes warmth, breathability and odour control.