The Vestil D-300-MD self-dumping hopper with bumper release is for storing and moving dry bulk materials. It is made of welded 10 gauge steel for strength, has a blue powder-coat finish for more durability than paint, and can hold up to 3 cubic yd. of material weighing up to 4,000 lb. The hopper can be moved with a forklift truck, and the attached safety restraint can be used to secure the hopper to the carriage of the truck. It automatically dumps when the bumper release contacts the side of a dumpster, or it can be manually released from the seat of the forklift truck with the attached cable. The hopper automatically returns to the upright and locked position after it is dumped. A second hopper can be stacked on top if it is turned 90 degrees relative to the bottom hopper. This self-dumping hopper measures 51 x 81-3/4 x 61 inches (H x W x D). (H is height, the vertical distance from lowest to highest point; W is width, the horizontal distance from left to right; D is depth, the horizontal distance from front to back.).