M-Series Library: How can I find the Product Serial Number?

How can I find the Product Serial Number for an M-Series Library?

The M-Series libraries are expected to go End of Service Life on 30-June-2011.  At the expiration of any existing contract, Quantum will no longer actively support them

For an M-Series Library, you can find the product serial number in three distinct locations:

Physical Location

The product serial number is located on either the Stack-link slot or on the back of the library, depending on the unit.