This Banjo Brothers bag offers a lot of options for the user. It is about 15" long by 6" wide (fully zipped up). It fits perfectly on a rear rack of any bike and gets secured with velcro, making it adjustable. This bag has a roomy inside compartment and expandable 1ft long panniers on both sides, giving you a lot of additional storage space. There is also an optional vertical expansion to the main compartment, yielding another 3.5" of usable space for those bulkier items. The rack top pannier bag is lined with reflective material, helping you stay visible on the road, and comes with a 30" carrying strap for off-bike use!