Design Philosophy The Women's Pakajak is a no-frills windproof shell that does as it says in the title - packs down into a tiny stuff sack (included) so you can carry it with you all the time, ensuring it is there when you need that extra bit of protection to keep you comfortable. Weather Ready Protection The jacket is constructed using a lightweight, windproof ripstop melange fabric with a durable water repellent treatment. The underarms use an open mesh to improve ventilation and comfort.