Have been using these filters for 4 years now. I just had a professional exam. The air conditioner coil was so clean the technician couldn't do anything. Today I will order the fourth filter. I installed the last one in November 2017. (I'm not saying you should wait that long). A few notes on quality: these filters are pretty reliable. Many cheaper filters can bend, snap, snag, or break during installation or removal if you're not very careful. They have retractable tabs on the side - not everyone has them - and they make a world of difference when it comes to maintenance. They have a lot more wrinkles than most. This makes the filter more efficient and lasts longer.
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