The closure mechanism on this crossbody bag is a zipper. The material of choice for this bag is nylon and it has a volume of 0.8 litre.
From Amazon
Fjallraven 23226-333 High Coast Pocket Gym Bag Unisex Rowan Red Size One Size
The product is available from £35.91 at international stores.
Trekkinn
Fjällräven High Coast Pocket Crossbody Red