The surface of the product is made by high quality Nylon plastic which are heatproof, high strength, insulative, damp proof and which is not easy to break also. It is also with planting cauterized surface. These products have very good quality switches. It is with the separate planting silver technique. Some of them are with automatic power, cut-off device which will cut the power if the product is over heat. It has double insulation protection, so it is very safe to use. low noisy.