Its simple its effective its versatile and its waterproof a waterproof cover for your rucsac or pannier in bright and reflective materials which is highly visible from the side and the rear this version contains an easily accessible external waterproof zippered pocket for all your essentials fits bags from approximately 15 30 litres capacity elasticated edging and press stud fasteners ensure that the hump fits snugly over your rucsac or pannier bag and will not flap around day glo yello