In the YouTube video of the Diversity audition you can see their elements of surprise (especially one of their two youngest dancers popping out of a duffel-bag midway through their performance).
The Italian-made Boston Classic Duffel Bag is a capacious canvas and leather bag with brass accents.
This Side Wheeler duffel bag is done in a rich, ruby/black color with delicate leather details; you'll look posh rolling this bag no matter where your travels take you!"
The Zurich duffel bag is a rolling bag made of smart and sturdy twill PVC.
In fact, some of the bags labeled as wheeled messengers more closely resemble a duffel bag.