Plus the long arm of the two-stage application: (1) pit, steep earthworks excavation, embankment, slope repair works. (2) municipal pipe network, pipe work project, the subway station, digging tunnels remote mining. (3) dredging canals, river dredging, dredging Hydropower tail, deep river silt, gravel cleanup. (4) Other depth, width, height, there are special conditions specifically requested. Plus the long arm of the two-stage process: a two-stage extension boom under the general common Q345B high strength steel manufacturing, design and simulation work, publishing materials, milling molding, assembly welding, pipe cleaning, inspection and other processes. Plus the long arm of the two-stage configuration: 20-25 tonnage excavator plus the long arm, can be extended to 16 meters, which is configured to: a bucket, a bucket cylinder, pin 6, high-pressure hose 4, butter tube 3, connecting rod assembly 1 set, a set of transport links, plus grow arm (8.5 meters), extended arm (7.5 m). 25-34 tonnage plus the long arm of the excavator, can be extended to 20 meters, which is configured to: a bucket, a bucket cylinder, pin 6, high-pressure hose 4, butter tube 3, connecting rod assembly 1 set, a set of transport links, plus grow arm (11 meters), extended arm (9 meters). 35-40 tonnage plus the long arm of the excavator, can be extended to 22 meters, which is configured to: a bucket, a bucket cylinder, pin 6, high-pressure hose 4, butter tube 3, connecting rod assembly 1 set, a set of transport links, plus growing up arm (12 meters), extended arm (10 meters) long arm excavator 40-50 tonnage, can be extended to 26 meters, which is configured to: a bucket, the bucket a cylinder, pin 6, high-pressure hose 4, butter tube 3, connecting rod assembly 1 set, a set of transport links, plus growing up arm (14 meters), extended arm (12 meters). The above configuration without counterweight, special needs, such as: 20 20 Mega tonnage excavators require modification of the long arm 25 or 30 tons excavators do you need to add Mega long arm assembly weight.