The Bosslifts by Herkules Air Jacks are designed to deliver reliable, heavy duty lifting power anywhere in the shop. These jacks employ an internal stabilizing cylinder and dual safety valves that help prevent over-inflation and uncontrolled deflation. Each jack is 100 percent air powered and has a lift capactiy of 4,500 lb. The AJ2 has a 6.5" lowered height and 13" raised height; the AJ3 offers a 7-7/8" closed height and 19-1/4" raised height. Optional 2" and 4" extensions are also available, along with a pinchweld adapter.