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. The Ortlieb Seat-Pack needs only six centimeters on your seat stem. That’s why the more compact model is ideal for smaller frame sizes, full suspension bikes and adjustable seat stems