This cover fits easily over the 120L bergan and has 4 male/female buckles to attach it to the webbing straps on the bergan. It is made of a thick cloth material which feels very durable. I'm not sure if it's waterproof but it looks like it'll take a lot of wear and tear. I only had to make 1 fix to the cover because on of the elasticated cords had come out of it's holder in the seams. Other than that I would recommend this cover. It fits very comfortably in the front pouch of your bergan when not in use.