With 500 GB of storage, this is a good HDD drive if you need a larger storage unit. This model's rotation speed is 7 200 rpm.
From Laptops Direct
HPE 500GB 6G 7.2k rpm SATA 3.5in Non-Hot Plug MDL HDD 1yr warranty - Black
Athema Services
hp 500 gb 6g sata 7.2 rpm **shipping new sealed spares** 659341-b21 -