This product is a combination of the fan's twenty years development, production technology research and development of new fans. The ventilation equipment, body compact structure, high efficiency, low noise, traffic, energy consumption, easy installation, and by the static and dynamic balance correction, smooth running characteristics. For the convenience of the user selection, the company developed the JD 9, JD 10, JD 12, JD 15, JD 18, JD 20, JD 22, JD 25, JD28, JD 30, JD 33, JD 36 and other models, and each model divided into several different configurations, have been used to meet the customers according to different environments to choose different types of fans, fans of the series by the Tianjin national fixed fire extinguishing systems and fire-resistant component quality supervision and inspection center pass.