https://www.on-running.com/en-us/products/climate-shirt-163/mens/creek-apparel-163.01032 Running, hiking, or a brisk morning walk – the lightweight Climate Shirt keeps off the chill, never overheats, and wicks sweat. Key features Weight: 203g The 100% recycled polyester mid-layer shirt Lightweight for maximum performance Adaptive fabric that works for both cool and warm runs Four-way stretch fabric for complete freedom 3D waffle construction for greater absorbency Fast-drying fabric construction Built-in thumbholes and watch windows