... long-lasting circulation. I. Features of DJF(a) series exhaust fan: 1. Fan blades are made of stainless steel, having strong air volume ... (24″), 780mm(30″), 830mm(32″), 900mm(35″), 1000mm(39″), 1100mm(43″), 1220mm(48″), 1380mm (54″), 1530mm(60″).6. We can customize ... shut flexiblyand steadily.III. Technical parameters of DJF(a) series exhaust fan: FansizeMotor rotational speed(rpm)Air flow (m3/h)Total ...