1 x Hard Drive Cover Type:HDD Cover Compatible Model:For Xbox 360 S Hard Drive Cover/Panel for Xbox 360 Slim Console ...

That doesn't mean there's no value in an external hard drive or SSD; instead, you'll want to use your chosen external device for Xbox One, Xbox 360, and Original Xbox games via backward compatibility.

Support for external hard drives over 16TB ... in addition to Xbox 360 and original Xbox, titles are supported, but tend to load a little slower than those on the internal drive.