A good day sized, waterproof, hiking backpack via MUCHUAN.  100% Cotton Canvas with Kapok which makes for a waterproof exterior.

Main Material: Canvas
Capacity: 20-35 Litre
Closure Type: Zipper & Hasp
Rain Cover: Yes
Style: vintage
Pattern Type: Solid
Color: Black, coffee, dark green
Backpack system: Curved Shoulder Strap