Cartwheel Duffel Bag Midnight Black. The go-to bag for all your fitness and overnight needs, we've refreshed this classic with new Gem quilting and enhancing the elements that we know matter most to you. A new buckle clasp on the yoga mat compartment means that removing and fastening your mat will now be a snap - literally. In addition, a larger storage compartment and a removable cross-body strap are two more of the added features we know you'll love us for.