This ShockWatch tilt indicator can be attached to packages which must remain upright during transportation. If the packet is tilted to either side, the little balls move into the next chamber. The recipient can then later check the degree of tilting the packet experienced during transportation. The upper row indicates tilting to the left, the lower to the right. The ball in the round indicator moves in to the outer torus when the packet is turned over 180°. Source: ShockWatch, TiltWatch Plus (company website)