"24V DC Cooling Fan" blades are made of a new material PP, AS new materials and recycled materials. First, we must learn to identify material or new material back: back to the material is processed by the injection of waste or expected from, there is a big smell, no environmental protection, low cost, becomes very brittle, fragile in cold weather, while not environmental protection. Identification of recycled materials is the most direct method of environmentally friendly materials is: if there is recyclable logo, indicating that the material is environmentally friendly new materials, if there is no explanation "24V DC Cooling Fan" fan is back feed material composition; "24V DC Cooling Fan" followed there is also a simple visual method: the new material because the material high purity, transparency is relatively large, back to the material by the impurity ingredients, so the less transparent, can pivot from one side to the other side!