Been using these filters for several years. Good collecting dust and airborne particles. I like buying the filters direct and quantities that last for a year or more.
Have not used yet. Our furnace man said I had been the incorrect type of filter--making our furnace work harder than necessary--and told me to use a filter that was not as heavy.
Filters are made great and really do the job of keeping my air clean from all the dust and allergens from pets.I will be ordering more in the future! J Weingard