[This review was collected as part of a promotion.] Easy to replace, good functionality, reasonable price

This item measures 4-3/8", not 4" and will not fit into my furnace. I am very disappointed because I trust this to be a great filter.

We've been using this air filter for over three years! It's an excellent product. I would not hesitate to recommend it to anyone.

I can't believe all the dust this filter picks out. I thought my old space guard was good, but this is better.

We have a relatively new construction and I'm always amazed at how dirty these get after a few months of use. That tells me they really work!

i change it every 6 mos and motor compartment looks like new which is the point if your compartment is clean your motor is too

I bought several 4" filters for my central Heating & air system. I have been very impressed with the performance of these filters.

I have been using these filters for over 2 years. They perform well, and it is so easy to simply change them every 90 days.

We've been using Filtrete air filters for a long time, because they really filter out the dirt and lint in the air.

i have used this product for 7 years. there is no comparison to this filter. i have saved money from technicians who would like to clean the unit.