In the landscape of outdoor bags, the Heimplanet Ellipse stands out like a sore thumb - but that's a very good thing. And that's because, not only does it offer 25-liters of storage and a water-resistant exterior, but it also features a construction designed specifically to cope with activity and movement. You see, the Ellipse is made to stretch and conform - thanks to a nylon spandex front layer - both to better suit your motion and to expand greater than capacity when necessary. It's also fitted with 3D molded back padding, features an internal sleeve for either a 15" laptop or a 3-liter hydration pack, and it's got hypalon reinforced stress points for extra durability.