Skyway Sigma 3 22″ Vertical Carry-On Luggage Bag for $29.99 shipped. Here is a screenshot for your reference. The Skyway Sigma 3 22″ Vertical Carry-On features Skyway’s Zero Gravity frame construction, which is supposedly stronger and 33% lighter than conventional metal frames. It is also expandable for an extra 2″ for additional room. It measures 21″L x 13″W x 8.5″D. Most places have it for about $47.