This pack is a No. 4 Monarch Duluth Pack, maybe their largest in really nice shape - last used maybe 4 years ago and it's a beast!
Take the standard No. 4 and add roomy pockets on each side! I used this pack less because I just never carry that much gear.
Perfect for stays longer than a week, it comes with the poly liner to guarantee your gear arrives and stays dry!
Can still find this on the Duluth Pack website - going for $599.00 these days.
Asking $350.00 or best offer