Had been using merv 8 filters. My system accommodates a slightly larger (4 vs 5) filter. Combined upgrade of size & merv value has much improved furnace effectiveness.
The quality of your product appears to be comparable with the more expensive versions that we've purchased at retail stores. We have yet to install them, and therefore cannot attest to their durability at this time.
Top notch, well-made product (Box of filters) arrived in good time...have installed one, so far, but the looks of the materials used in manufacture give me confidence that the outcome will be quite satisfactory. I'll update the comments as we use the filters. Given that we're in an area where Summer Brush & Forrest fires are often a problem, this should provide a good basis for comparison with other brands we have used. Thanks for your interest! Richard