BlackJack,13653 Cabinent Pocket Door Hinge Set - 22' (set for one door) 14566
Wood stabilizer (1/2" thick, customer supplied) joins the two slides to prevent racking.
A door of the same width as the slide (i.e. 18") will protrude 3" past the front of the cabinet when it is in the pocket. This prevents the knob from hitting the front of the cabinet. For narrower doors, simply restrict the travel of the slide with a stop block.