Which type of hydraulic tool has at least one movable arm to move material?

Spreaders are hydraulic tools specifically designed with at least one movable arm, which allows them to open and spread apart materials. This capability is particularly important in rescue operations where the goal is to create space, such as in vehicle extrications. The arms can be operated in various configurations to apply force, enabling responders to pry open doors or create access points in wreckage.

In contrast, cutters are primarily used for slicing through materials and do not feature movable arms for manipulation. Pump motors are mechanisms that convert hydraulic fluid into mechanical power to drive other tools, while compressors serve to compress air or gas and are not designed for moving materials in the same manner that spreaders do. Thus, spreaders stand out due to their specific feature of having movable arms for manipulation tasks, making them the correct choice.