The boom of this series of elevators has compact structure and adopts new high-quality section steel. It has high strength, light weight, direct access to AC power supply for startup, fast erection speed, automatic hydraulic support foot, fast erection, safety and simple operation. The working area can be raised and extended horizontally, and the span is large to increase the working area; It can also be rotated and the platform is automatically leveled. It is easy to cross obstacles to reach the working position. It is an ideal equipment for climbing.