1, Germany Bole Xinfeng: Founded in 1900 and headquartered in Munich, it is a company specializing in indoor ventilation solutions with more than 100 years of history and experience.

2. Seiko, Germany: focusing on ventilation system, adhering to the excellent tradition of Bavaria, is committed to providing a real constant oxygen, constant temperature, green and healthy comfortable environment for every family.

3. Northenberg, Germany: the first brand in the fresh air system market in Germany, providing high-quality fresh air system products and solutions.