As Topeak say, this is 'the big one'!Ideal for touring cyclists or for commuters the Trunkbag DXP is based on the popular MTX DXP, but with velcro mounting straps. 600 Denier Polyester Dupont Teflon Coating for superb weather resistanceExpandable, divided main compartment with two side panniersPadded foam walls protect loadElastic top bungees3M reflective strip for safetyBuilt-in carrying handle, plus detachable shoulder strapCompatible with all rear racksSafety light clip36x25x21.5/29cm22.6L995gThe expandable, divided main compartment with two sides offers plenty of storage space while the extra thick rigid foam sides, top and bottom ensures any valuable items stay protected. 3M reflective trim helps to keep you visible in low light conditions while the safety light clip gives you the option to clip on a rear light. As well as being a great on the bike bag it can also be used off the bike thanks to the built in carry handle and detachable shoulder strap. Compatible with all rear racks