The Ortlieb Seat-Pack is a key item in your bikepacking setup and it comes with Velcro straps to enable convenient and secure mounting to your seat post. Projecting backwards from the seat stem, your Seat-Pack also serves as a rear fender. The spacious, waterproof Seat-Pack keeps its contents safe and dry. You can conveniently adjust the volume of your pack from 8 to 16.5 liters by adjusting the roll closures on the sides. An additional valve allows you to quickly and easily compress your soft gear for a more compact fitThanks to its elastic drawstrings on the top, the 16.5-liter model offers additional space for items you need to be able to access quickly. This model needs only 15 centimeters of space on your seat stem.