Disclosed is an apparatus and method for restraining flat objects such as semiconductor wafers within a cassette placed inside a box or pod to prevent movement or vibration of the flat objects during storage or transport. A flexible or inflatable tube contacts and conforms to the edge of the objects to eliminate movement and provide vibrational damping without hard surface contact or damage. The tube may be deflated or removed from contact with the wafers to allow removal of the wafers from the cassette.
