A grab is a specialized tool for a crane to handle dry bulk cargo. It consists of two or more hinged, bucket-shaped jaws that close together to form a cargo space. During loading, the jaws close over the material pile, and the material is caught in the cargo space. During unloading, the jaws open while suspended above the material pile, allowing the material to fall onto the pile. The opening and closing of the jaws are typically controlled by the crane's hoisting mechanism's wire ropes. Grab operations require little physical labor, achieve high loading and unloading efficiency, and ensure safety, making them the primary bulk cargo handling tools at ports.