A method for enhancing an aerodynamic performance of an unmanned projectile. The method includes receiving the message, identifying all items of a certain type in the message, determining whether each of the items meets a criterion, and in the event that all the items are determined to meet the criterion, determining a classification of the message. The fastener can be a nut, and the containment layer can be disposed around one or more of the top, bottom and side surfaces of the nut. The elongate shaft further includes an additional at least one aperture formed in the tubular wall generally adjacent the second end also and in fluid communication with the shaft cavity. As the one or more wafer holders rotate about the axis of rotation through the chemical in the container, the wafer holders remain in a substantially constant vertical and horizontal orientation. This joint mechanism joints the first casing and the second casing in an openable manner, and joints the first casing and the second casing such that the display unit can be shifted in the open state between the transversely long state and the longitudinally long state with respect to the first casing.