Industrial storage products include cabinets, containers, coolers, carousels, garages, hoppers, lockers, mezzanines, racks, shelves, shelters, storage tanks, and walk-in enclosures. Cabinets have access doors or drawers for containment and/or security. Containers are used for the storage and/or transportation of bulk materials. Coolers are insulated to ensure the proper temperature of stored products. Carousels are mechanized or automated and have a single access point. Garages have large entry doors for storing machinery, vehicles and equipment. Hoppers allow material to be dumped or dispensed. Lockers are used to store material in secure areas. Mezzanines are intermediate structures between the two main stories of a building. Racks and shelves include cantilever racks, gravity racks, reel racks, pick racks, drive-in racks, pallet racks, multi-tier racks, bar racks, flow racks, storage racks, and other rack types. Shelters are designed to house and protect instrumentation or personnel.  Storage tanks are general-purpose, bulk storage containers. Walk-in enclosures are industrial storage structures that permit operator access. They often contain power generation, communications, or X-ray equipment.