They say that in uncertain financial times like these, companies that sell replacement parts, and places that do repairs do great business. Instead of replacing a piece of equipment, people will just repair what they have.
This is especially true of appliances. Sometimes it is cheaper to buy a replacement part instead of a brand new item, like a refrigerator.
When we moved into our house, we put out old Whirlpool refrigerator in the garage. Turns out the replacement filter part number is 4396841. How do I know? We had to replace it!