1. Material: the material of the big and small arms is Shaogang q**5b, the iron pipe on the arm is national standard cold drawn seamless pipe, the pin shaft is *0Cr, the high-pressure hose is a joint-venture pipe with 4 layers of steel rings, the grease pipe is a single-layer hose, and the bushing driven into the base of the boom is graphite alloy copper sleeve.

2. Configuration: one set of big and small arms, six-pin shafts, four high-pressure hoses, three grease pipes, one set of connecting rod assembly, one bucket cylinder and one bucket.

3. Product advantages: plasma cutting, machine milling, robot welding, boring after welding, assembly line production operation, and better quality assurance. It can be customized according to the working conditions to meet the construction needs of different users. The opening angle of the large and small arms can reach **3 degrees, and the excavation radius and height are larger.

4. Working conditions applicable to the lengthening arm: Municipal Engineering, subway construction, river dredging, reservoir cleaning, and other water conservancy projects.