The Topeak DynaPack DX Saddle Bag offers a spacious, near TrunkBag capacity without the need for a rack, making it perfect for cyclists who need extra storage on their rides. This larger version of the DynaPack features an expandable top that can hold a helmet, shoes, or other large items. Molded from rigid EVA foam and 600 denier polyester, it maintains a sleek, aerodynamic shape while providing durability and water repellency. The divided main compartment and additional zippered pocket help keep your items organized. The lightweight aluminum exo-frame with a quick release mount attaches to seatposts measuring 24.5 - 34.9mm. Additional features include a convenient carrying handle, 3M reflective strip, and a rear light clip for extra safety.