Inertia Trail Wedge Expandable Bicycle Saddle Bag Zippered expansion baffle increases bag's capacity by 25% DuPont Cordura fabric with rear strobe loop Extra long cinch strap for storing bulky items below the bag Top, front and sides are lined with 14 oz truck tarp vinyl for bombproof durability 7" x 4" x 2.5-4", 58-79 cu.in.