Sumner ST-802 780376 Heavy Duty Hi Jack Pipe Jack with 28-Inch - 49-Inch Height, Roller Head And Fall Guard. The first commercially produced Jack stand constructed of rugged 1-Inch steel tubing, tested by independent labs for excessive loads. Backed by over thirty years of jack stand manufacturing experience, Sumner offers their patented Fall Guard feature, allows 1-Inch (25 mm) safety zone around lock washer and 1-1/2-Inch (38 mm) Acme fine adjustment thread is the largest in the industry. Large, convenient adjustment handle, set screws for double margin of safety (set screw can lock jack head to stand for transportation with no loose pieces.), and quick action lock washer for fast height positioning round out the features.