It can be directly installed on the air duct and connected with the air duct. When the fan is running, the valve is opened and the air flow passes smoothly. When the fan stops, the valve is closed to prevent the air flow from reversing.

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  CCCF certified products

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  CMA metrological certification

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  National quality supervision, inspection and certification

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  China recognizes the joint symbol of international mutual recognition

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  China recognizes the joint symbol of international mutual recognition