Different types of trails call for different layers. Our lightest mid layer, made with over 90% recycled polyester, is designed for complete comfort when heading out on the cooler days. The special waffle grid looped backside structure provides thermal comfort and helps wick away sweat from skin. The longer backside makes it backpack-compatible without riding up and the close fits sits under other layers without impacting your movement.KNOW THE CARBON FOOTPRINT: All life cycle stages have been considered in our product carbon footprint calculation methodology and is based on the adidas' prototype size. From raw material extraction, processing, production & assembly, packaging, transportation, use and though to the end of the product's life, we measured the carbon footprint (CO2e).