These requirements cover cord and plug connected@ indoor use@ dry location Merchandise Display and Rack Mounted Power Distribution Units (MDRMPDU). They are intended for use on merchandise displays@ racks and gondola shelving systems in retail stores to provide power for computers@ audio and video equipment and other electrical utilization equipment that is displayed on the merchandise display@ rack or gondola shelving unit. A MDRMPDU is not intended for use in general applications. These units are rated 250 Vac or less@ 20 Amp or less@ single phase for use on single circuits only. MDRMPDUs may be extendable. Merchandise Display Rack Mounted Power Distribution Units are not for use: a) At construction sites and similar locations; b) As a substitute for fixed wiring of a building or structure; c) For routing through walls@ windows@ ceilings@ floors or similar openings of buildings or structures; d) For attachment to buildings or structures; e) When concealed by walls@ floors@ or ceilings; and f) Where subjected to physical damage.