Osprey Atmos Pack 50L, good condition, size L good condition.
This pack carries extremely well, I just don't like the ice tool attachments.  Osprey also has their external "destroy it and we'll replace it" guarantee.
$100

Amazon link with specs:
https://www.amazon.com/Osprey-Mens-Atmos-50-Backpacks/dp/B00XN1T1NKOsprey Atomos Pack 50L, good condition, size L (edited).