Have you ever thought that when you walk into the company, the supermarket, or the MRT, every space in your life and the air you breathe in has an invisible gatekeeper, providing us with cleaner air quality all the time. This time, the special correspondent of the China Clean Technology Association walked into Central Taiwan and came to the center of Taiwan, hidden in Nantou - the indispensable clean air hero - the king of AIRREX clean room filters - Shengding Technology.