A new piece of apparatus is on the roster at O’Hare Airport. 9-2-4, though not yet in service, is a Tempest mobile ventilation unit with similarities to 9-2-3 at Engine 106’s house. 9-2-4 has a fan unit with a smaller volume and is mounted on a Ford F-250 chassis with a small body. Whereas the 9-2-3 has the Tempest MVU-60 (60″ fan), 9-2-4 has the Tempest MVU-125 lightweight model.