1. Optimized design, 2. Big air volume, low noise, litter energy-lose, 3. Stable running,steady long-lasting circulation. I. Features of DJF(a) series exhaust fan: 1. Fan blades are made of stainless steel, having strong air volume, being non-deformation, non- fracture, attractive and durable. (blades are originally made of aluminium alloy. But because of the low metal fatigue of aluminum alloy ...