Mini-Load AS/RS systems are smaller systems and typically allow selection of items in totes, trays or cartons. AS/RS systems are configured with pallet rack laid out with narrow aisles between. Sometimes there is a raised metal rail down the centre and a tall mast travels through the aisle along the rail. When the mast reaches the storage location, an AS/RS carriage travels up the mast to the picking spot. An automatic mechanism then reaches into the storage location to retrieve or return the load.