A freight lift is used to carry goods only, though some do both to allow operators and those loading goods along for the ride. Freight elevators are typically larger and capable of carrying heavier loads than a passenger elevator, generally from 2,300 to 4,500 kg. Freight elevators have manually operated doors and often boast rugged interior finishes to prevent damage while loading and unloading. Although hydraulic freight elevators exist, electric elevators are more energy-efficient for the work of freight lifting.