The litter is a class of wheelless vehicles, a type of human-powered transport, for the transport of people. Smaller litters may take the form of open chairs or beds carried by two or more carriers, some being enclosed for protection from the elements. Larger litters, for example those of the Chinese emperors, may resemble small rooms upon a platform borne upon the shoulders of a dozen or more people. To most efficiently carry a litter, porters either place the carrying poles directly upon their shoulders or use a yoke to transfer the load from the carrying poles to the shoulders.