An intermodal container is a large standardized shipping container, designed and built for intermodal freight transport, meaning these containers can be used across different modes of transport - from ship to rail to truck - without unloading and reloading their cargo. Intermodal containers are primarily used to store and transport materials and products efficiently and securely in the global containerized intermodal freight transport system, but smaller numbers are in regional use as well. These containers are known under a number of names, such as simply container, cargo or freight container, ISO container, shipping, sea or ocean container, container van or (Conex) box, sea orc can. There is a large range of sizes available. Common ones are 20' or 40' in length x 8' wide and 8'6" high giving a nominal volume of 1,360 cubic feet (38 m3) and 2,720 cubic feet (77 m3) respectively. 10' and 30' lengths are also available as are half heigh and third height for all lengths. They are normal end opening although top opening variants are also available.