Deuter Gravity Expedition 45+. The years of experience and extreme demands of our expedition professionals Gerlinde Kaltenbrunner, Dominik Müller and Kazuya Hiraide were the basis for the minimalist, highly functional Gravity Expedition with bluesign® certified main material. The lightweight backpack can be slimmed down even further by removing the Delrin® U-frame or backpack lid if needed. The Light back system is also stripped down to the essentials while allowing you to carry heavy loads comfortably. The extra-light hip fins are also equipped with gear loop, Ice Clipper loop and zippered pocket.