The Heavy Duty Jack is the first commercially produced Jack stand constructed of rugged 1" (2.5 cm) steel tubing, tested by independent labs for excessive loads. Standard Features: 2,500 lb (1,135 Kg) capacity - 3,500 lb (1,580 kg) capacity for Heavy Duty Plus Jack - Strut tension plate for superior lateral support - 1" (2.5 cm) square tube base construction - Built for heavy use & abuse - Quick-action lock washer for fast height positioning - Patented Fall Guard™ feature allows 1" (25 mm) safety zone around lock washer - 1-1/2" (38 mm) Acme fine adjustment thread – the largest in the industry - Large, convenient adjustment handle - Set screw for double margin of safety - Set screw can lock jack head to stand for transportation – no loose pieces - Jack independently load tested for quality assurance - CE rated - Backed by over forty years of jack stand manufacturing experience -