The present invention provides a unique method and user interface that facilitates accessing and browsing objects in which a user begins with a center object displayed on a screen and related objects are populated on the screen as well. Each contact piece is provided with a horizontal U-shaped or a horizontal V-shaped intermediate region having a folded end portion and a pair of arm portions vertically spaced apart from the folded end portion; a first tip region extending downward from the tip portion of one of the arm portions; and a second tip region extending upward from the tip portion of the other arm portion. The vertical members anchor the fastener strip to an object during molding of the object and form an effective seal against fouling of the fastening elements. The first control panel is provided with a first operating part for setting operating conditions of the rotator part including the desired rotating speed of the rotor and the desired operation period of time of the rotor, and a first display unit for displaying the operating conditions and status of the rotator part. One or more tiers may be mounted, using various locking mechanisms, onto the cylinder to divert flow of the medium.