ECO filter is second only to PRO filter in terms of performance, yet it is more economical than F96. It is the best value for money in terms of performance/cost ratio.

Items included:
10 pairs of ECO Filters
A pair of pre-installed ECO Filter+Frame
Blue Filter cover

The ECO filter is the most cost-efficient for high performance for air pollution (PM2.5).
The larger filtering area ensures easy breathing.
Original price $35. Now promotion at $25!

More info:
https://www.youtube.com/watch?v=wr_6KQCbGHM&t=3s