OKFIL Window Filter is an innovative energy-independent fresh air supply valve with air purification. Round-the-clock (24/7) ventilation with closed windows without dust and noise. International patent pending technology. Looking for EMEA, APAC, AMER distributors for OKFIL Window Filters. Write a personal message to Denis Dmitriev. Facebook International Page - https://lnkd.in/eGx7mQp International website - https://okfil.com E-mail - info@okfil.com