Look what I found:
"Granite Gear had specially designed a pack for us to use for this trip based on
our specs and the conditions we would be seeing. Weight, durability and comfort in
hauling heavier loads were are main objectives when working with Granite Gear.
We also wanted ease in carrying technical tools and our alpine kit. What they came
up with is probably one of the most state of the art backpacks on the market today.
Made of pure spectra dyneema and with a few accents of cuben fiber, the pack
material has the perfect blend of durability and weight ratio. We knew we could not
afford to have any sort of pack failure on a trip of this nature, so trying to cut
corners and use traditional weight saving fabrics like silnylon, lighter weight cuben
fiber, or even Codura nylon blends would not have been acceptable. The frame sheet
Granite Gear put together is nothing short of remarkable. Made purely of carbon
fiber and based off their award winning Nimbus Topflex line of suspensions, this
framesheet alone cut around a pound off of the suspension. Total weight for the
pack was around 33oz with a volume of around 50‐60L."