The structure of the product consists of fixed body，sliding body, telescopicoil cylinder and so on. The fixed body is connected with the excavator boom andbucket rod oil cylinder; the sliding body is connected with the bucket through the oilcylinder，rocker and connecting rod; it is generally used with the bucket tocomplete the excavation of deep pits and open caisson; it can also be used withthe grab bucket to grab soil, sand and coal.

Two inner telescopic boom