Wisdom is the manufacturer and research institute of Guide-vents and Total Heat Air to Fresh-Air Exchangers, it is the well-known trademark, and the company is very experienced in designing and manufacturing for more than 30 years, the technology is in the lead of the world levels. It has several patented skills, the standards of products is completed. The Total Heat Air to Fresh-Air Exchangers include the types in outside, which is sectional, person who is hang, and the falling one. They have perfect craftsmanship?the company have been passed through the authentication by ISO9001.The function of products have reached the world standards, they have great success in noise, wind amount and characteristic of airflow.