If I buy this, will I have room to put a backup hard drive (non-ssd) in it?

There is no information available about additional room for a backup hard drive (non-SSD) in the provided product information.

Questions & Answers: Refurbished: Dell OptiPlex 9020 Tower 4th Gen Intel Core i7-4770 3.4GHz 16 GB RAM 512 GB SSD DVD-RW Windows 10 Professional 64-Bit

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Dell OptiPlex 9020 Tower 4th Gen Intel Core i7-4770 3.4GHz 16 GB RAM 512 GB SSD DVD-RW Windows 10 Professional 64-Bit