The X-case is the optimal accessory bag to carry chargers, cables, & other extras you need to access quickly. The X-case Large adds 3.5L of packing space to your backpack. The case mounts to the lumbar curve of the Boblbee hardshell backpacks. It's well protected & insulated with aluminum foil to keep your lunch or snack fresh while you're on the go. Reflective striping on all sides increases visibility & double parallel zippers allow easy & quick access. The X-case is an all-around excellent accessory pack for your Boblbee pack! Compatible with Boblbee 25L GT, GTO GTX as well as previous Megalopolis model.