Shenzhen STORM science and technology company specializing in the production of various DC fan, AC fan: DC sizes: 12 / 18 / 24V impeller diameter: 30mm, 40mm, 50mm, 60mm: 90mm, 150mm, the length of 220mm, 250mm, 300mm, AC sizes: 110 / 220V: 30mm, 40mm, impeller diameter 45MM, 50mm, 60mm: 90mm, 150mm, the length of 200mm, 250mm, 300mm, 360mm, 420mm ( another 300mm do double impeller ), AC motor can be added outside with a blade to the descending motor temperature rise. AC fan can also speed gear, most do . 3. Connection: socket type or lead type. Bearing: oil or ball can be. Other speed, current: customers may request the production.