These jacks feature an adjustment range from 11 3/5 inches to 16 1/10 inches. The minimum and maximum height capacity reaches a total of 8800 lbs (4 tons), enabling them to bear heavy loads. The base plate measures 5 inches by 5 inches by 0.19 inches, with a hole diameter of 0.5 inches, while the top plate is sized at 3 inches by 3 inches by 0.19 inches, ensuring a stable contact with the supporting surface. In terms of installation, simply keep the base plate stationary, swivel the top plate to the required height, and then tighten the positioning nut with a wrench to secure the top plate. Even a single person can complete the installation and start using it within seconds. Constructed from heavy-duty steel with a zinc-plated surface, these adjustable support jacks offer excellent corrosion resistance and durability, allowing them to work stably in various environments.