Got a bad back? No worries. Just pick up a set of our optional casters and snap 'em into the base plate. Attach the pull strap to the handle and presto... an easy rolling Cube Case! When you get to check-in just unclip the casters, insert into the bag, and toss'em into the cube case. Say goodbye to your chiropractor. Four removable casters with mounting plates, pull strap and nylon carry bag included.