Prepare for your upcoming bikepacking adventure with the ORTLIEB Seat-Pack, a crucial component in your bikepacking setup. This waterproof and spacious pack attaches securely to your seat stem using Velcro straps, also functioning as a rear fender projecting backward. The pack's volume is adjustable from 8 to 16.5 liters or 4.5 to 11 liters, depending on the model, providing flexibility for different trip durations. Additionally, the Seat-Pack can serve as a replacement backpack for day trips, accommodating various bike types, and is available in two sizes, with the smaller model suitable for smaller frames and adjustable seat stems. Other features include reinforced fabric, a vertical daisy chain for a rear light, compatibility with carbon seat stems, a lightweight design, and four 3M Scotchlite reflectors for increased visibility.