With this expanding design, users could turn a trip around town into a shopping spree. Features: Includes a detachable shoulder strap, a loop for a safety light, and an internal key clip, and coin pocket Expandable from 900 to 1300 cubic inches with a drop-down pannier on either side Thick padding insulates snacks and protects gear Fits most rear-mount bike racks Ripstop fabric upper with rugged ballistic bottom panel Offers more visibility with 360 degree reflective accents Specifications: Pack Type: Trunk Bag w/ Expandable Pannier Pockets Pack Capacity: 14.7L (Unexpanded), 21.3L (Expanded) Mount: Straps Waterproof: No Material: 840D Polyester Dimensions: 14.5 x 5.5 x 7" (Length x Width x Height - Unexpanded) Color: Black Weight: 771g