A cleaning device for cleaning the exterior of at least a part of a milking parlour. The first aircraft is adapted for determining coordinates of a position of a waypoint. When a predetermined command is transmitted to the second device from the first device, and a command is transmitted to the second device from the communication terminal, the second device executes a process with respect to the command, and predetermined data processing can be requested to the first device. The compositions are added to the vinyl aromatic monomer in amounts sufficient to prevent polymerization during the distillation process. The extended diameter is larger than a diameter of the linearly extruded segment, and the enlarged diameter is larger than the diameter of the linearly extruded segment.