This is a beautiful item, purchased from Montbell at the end of last year and used only once for hiking. I believe it's the 4-liter version, but please confirm with the images. Below is the product description: This lightweight and sporty waist bag is perfect for hiking and walking. The side compression straps, when tightened, prevent the pack from swaying, providing excellent stability. It's also packed with storage features, including convenient pockets for small items and straps to secure a windbreaker. It also has a key leash inside a pocket, which is convenient for attaching keys.