These jack stands are made with a formed and welded steel base for strength. It has a self-locking ratchet handle that cannot be released under load. Durable baked enamel finish resists corrosion. Stands conform to ANSI PALD load rating standard; factory tested before shipment. Pair of 6-ton jack stands. Base: 10-5/8 inches x 9-1/4 inches. Height range: 15-5/16 inches to 24-5/16 inches.