Lone Peak's Mini-Expandable Seat pack features a main compartment that is expandable when lower zipper is opened. Made from rugged, water resistant 1000 Denier Nylon, the expansion gusset allows for larger load carrying capabilities. Hook and loop seat post connections and EZ off 2-buckle quick-release suspension system easily attaches to seat. A molded polyethylene stiffener is placed internally within a sleeve on the top and the bottom for added ruggedness and pack integrity. 3M Scotchlite reflective material and a Lone Peak taillight hanger gives you added visibility at night. Coverlight truck tarp is used on the top of the pack against the seat rails for the ultimate in abrasion resistance. Perfect for wallets, keys, tools, tire levers, patch kits and other cycling must-haves.