Mixed Refrigerant R404a is 1.As long-term substitute for R22 and R502, 2.Used in refrigeranting systems of L&M temperature Refrigerant R404a isAs long-term substitute for R22 and R502, R404A is used in refrigeranting systems of low& moderate temperature.As a manufacturer,1. Give you the lowest price2. Provide the best quality products3. The best service.