The MIK Big Poppa is our biggest rack bag for maximum cargo. It comes with a large main compartment with a seam-sealed liner, making the internal bag waterproof and drop down panniers on each side with expandable top making this the biggest we know of. - RF seam sealed internal liner - MIK Mounting Bracket attached - waterproof zipper on main storage compartment - water bottle/drink holder that will fit multiple size bottles - bungee net on top for added storage - drop down expandable side panniers - expandable top - shoulder strap included - reflective accents - Designed to fit most racks - dimensions: 15" x 10" x 8" (with panniers) - Fits racks up to 7.5" wide - 1600 cubic inches, includes panniers