A power supply includes a current supply, a plurality of output channels, and a controller. The closing system provides lubrication for a piston rod without a need for periodic replenishment. The diaper has a discrete edge seal folded about and joined to the longitudinal edges at least at the portions defining leg openings when the diaper is worn. These optical elements are clamped by four clips from the two directions of up and down in a state of being stored in the unit frame.