This type of accumulator can be dual or single flight. The dual vertical accumulator can handle heavier objects because it has more support. Vertical accumulators lift the product up on a set of shelves, then release rows of product; shelf by shelf. The first items to enter the accumulator are the last ones to be released. Some vertical accumulators are round, and convey the product down a spiral, such as alpine systems, which lift or lower product to a lower or higher line. Product can also be heated or cooled as it travels along the accumulator. Vertical accumulators conserve floor space by taking advantage of overhead space.