Our Burra Burra Stabilizer Seatpack 20 is the largest in our line which means that you can say goodbye to the cumbersome weight and handling of integrated rear racks. Instead it affixes to your seatpost via an engineered aluminum stabilizer arm that minimizes any bouncing or side-to-side swaying under load. The pack itself features a welded roll closure design that's highly resistant to inclement weather while its larger size (55x19x10cm) makes it ideal for mid to larger sized frames.