Product review (5 stars): Not exciting but necessary
Most of you that use a furnace for forced air heat probably have a Humidifier mounted on the side of your furnace to add moisture back into the air to keep wood floors, furniture and picture frames from drying out and to make your living space more comfortable.  If you do, to get the most benefit you need to change your filter.  It is very easy to do if you order the right size.  Just get the humidifier model number and look on Amazon.  The price was good and the service fast.