The King screw Jack was conceived as a tough lightweight jacking device to replace awkward and heavy floor jacks carried onboard race vehicles. The King screw jack is a mechanical design that does not rely on hydraulic fluid to lift your vehicle and has a weight capacity of up to 3800 lbs. The screw actuating nut is the same ¾" hex size that your lug nuts use. The screw jack can be raised or lowered by your existing electric impact gun or lug wrench without changing sockets for quick wheel changes. The jacking boss is adjustable up and down on the jack body to compensate for the height of your vehicle. The jacking range is a full 16" to provide enough ground clearance for even the tallest tires.