This series of products are applicable to the underground mine for press local ventilation. They are also applicable to similar environment of road, railway, defense enginnering, water resources, metallurgical Industry. There are explosion-proof and common types according to the requirement of the users. The performance of the safety of the products conforms to the Chinese Standard of GB3836 and the Ex-marking is 'ExdI' or 'ExdIIBT4'.