You close this hiking backpack with a zipper. The material of choice for this bag is nylon and you can put various small items in the inner pocket.
From Ordnance Survey
Osprey Talon 11 Men's Daypack - Black
The product is available from £59.76 at international stores.
Trekkinn
Osprey Talon 11l Backpack Black L-XL
This product is also available at 2 unverified merchants.