They are advertise for the April Aire 2400 replacement. The filter is not tight and air can go around it defeating the purpose of the air filter. I had to put pipe insulation on top of the filter to fill in the gap and duct tape it to get an airtight seal.
Quick service! Filters look to be made well. Though, I wish they could be wrapped individually when buying them in bulk. Otherwise, awesome product, Thank you again!