The atlantic compass unite collection features the link 2 go system which allows you to connect luggage back to back with velcro straps and roll two pieces with just one hand, or comfortably roll four pieces at once this 21 inches expandable upright spinner suiter is a breeze to travel with, featuring spinner wheels that allow for 360-degree movement with zero little effort, built with quality construction features like, durable crash-guard wheel housings, skid bars and corner guard, that are back by a 10 year warranty