The filter was an exact fit, was of very good quality. I did learn two things.Don't try to replace the filter when the fan is operational, there is so much suction you can't slide the filter all the way into place. You can also feel how bad the old filter needs to be replaced when you try to move that in the channel with the fan on!
An old a c repair mechanic here. I worked for 38 years in commercial buildings and have handled thousands of filters. These are as good as I ever saw and at a very fair price. I like them so much I started a subscription !