This tail bag can be secured either on the rear seat or the luggage rack、 which is located under the rear seat. A zip expands the bag to up to 25 litres of volume. In addition、 there is an elastic cord which can be used to store wet rain gear、 a Velcro fastener on the plastic piece of the rear frame and an outside bag for the little things youd otherwise find yourself searching for. With the eyelets on the tail bag、 its possible to easily tie down an object to the top of the bag. This tail bag can be converted to a backpack using the included straps. Colours: black、grey Dimensions: approx. 35x30x15/26cm Volume: approx. 15/25 L Made of Teflon-coated CORDURA、 therefore water-repellent.