Silhouette Sphere 2 Set Boarding Bag And 21 Spinner Size:21" contoured handle flexibly fits each contoured handle flexibly fits each travelers physiology while the best in class wheel system with steel cartridge bearings creates an exceptionally comfortable and smooth travel experience Technology that removes the bulk and weight of the insulation which increases mobility Each half of the sphere wheel can move independently in the same or opposite direction to comfortably allow rolling over uneven or smooth surfaces alike with the same effortless motion for the ultimate in unparalleled control and turning ability Introducing the new silhouette sphere 2 featuring Samsonite's new split spherical wheels