As light as "air" [Küki in Japanese] at 172g/6oz (size M). Designed primarily to serve two purposes; as a stand-alone “sweater” when lightweight and packability is the goal such as long distance & duration runs/hikes/bikes and as a perfect mid-layer under a shell when a normal puffer/down jacket is too much. A full length center zip (two-way) provides many ventilation options. 

A casual “sweatshirt” fit slides easily over a tee-shirt or base layer. Wear it around the house when your partner won’t turn up the heat.