You use a zipper to close this bag. Maybe not a good choice if you prefer lots of colour choices, but it does come in orange.
From Osprey Europe
Transporter® Waterproof Duffel 40 - Mars Orange - One Size
Ellis Brigham
Osprey Transporter 40 Waterproof Duffel - Mars Orange
Trekkinn
Osprey Transporter Wp 40l Duffel Bag Orange