Osprey Porter 30L Carry-On Travel BackpackPorter 30L Carry On Travel Backpack The Porter 30 offers the comfort of a backpack along with the functional simplicity and storage capacity of a duffeland does it all in an attractive, durable package. Whether youre tossing it in a car, shouldering it on a train or carrying it on a plane, padded sidewalls help to protect inner belongings and StraightJacket straps compress contents to a smaller size. Deploy backpack style carry when you need it to