The invention provides a method of adjusting a rotational balance of a once through fan for a gas laser apparatus. The reinforcement includes a wire and, optionally, an outer wrap. Possible agitation elements include traditional stirrers, rotating magnetic rods, bladder devices integral with the structure of the container, as well as different devices for manipulating the shape of the sealed container. The absolute information may identify a transmitter. According to the present invention, when shopping on-line, a user of a communication terminal may purchase a commodity easily. During shifting, one servo controls the zeroing of the difference between the speed of the engine and the speed of the gearbox output shaft as required by the gear ratio of the selected gear pair.