A mortar can be moved around by one or more people (bigger mortars can usually be broken down into parts) or moved around in a vehicle. An infantry mortar can usually be set up and fired from a mortar-carrier. A mortar-carrier is a modified armoured vehicle or one built especially to be a mortar-carrier. They have a big hatch on the roof. Mortars with two barrels—like the AMOS PT1—are the latest kinds of heavy mortar. They are put on carriers such as armoured personnel carriers, tank chassis and patrol boats.