Reducer is a mechanical transmission device in many fields of national economy, industry-related product categories include various types of gear reducer, planetary gear reducer and worm reducer, but also include a variety of special transmission devices, such as growth devices, speed control devices, including flexible transmission devices, such as various types of composite transmission. Products and services related to metallurgy, non-ferrous metals, coal, building materials, shipbuilding, water conservancy, electricity, engineering machinery and petrochemical industries.