Rev-A-Shelf RAS-ML-HDSC Appliance Lift with Soft-Close Mechanism, Chrome Package Contents:(1) Heavy Duty Lift (Assist) System and mounting hardware Should not be used in cabinets above 21" Assembled dimensions: 5" W x 5" D x 5" H Can be used with many different widths with a minimum base cabinet frame opening of 12.5" Full height cabinet required, simply supply your own custom shelf Spring loaded system gently assists the movement of small appliances to counter height