The Unite 2 21" EXPANDABLE SPINNER luggage features the Link2Go in its upright spinner models, which is a innovative way to attach two Spinners together. It's easy, just connect the Spinners back-to-back with Velcro straps and you're ready to roll multiple suitcases with one hand. Amazingly versatile and lightweight, the affordable Unite 2 is perfect for family travelers who need an extra hand. Now busy families can roll more pieces, more easily. Connect luggage back-to-back and push two pieces with one hand!