Is the Optical Bay SATA Hard Drive Enclosure compatible?

I have a mid-2010 unibody 17" MacBook Pro, model A1297. I would like to add a second hard drive in place of the optical drive.

I attempted to install a 9.5 mm SATA Optical Bay SATA Hard Drive Enclosure, but found that the new hard drive enclosure lacks the two screw holes that are present on the original optical drive near the edge of the laptop case. I don't feel safe installing the new hard drive enclosure without it being properly secured inside the laptop.

Is this new hard drive enclosure truly compatible with my MBP?

Thanks in advance for any help.

Edit: added picture of the hard drive enclosure next to the optical drive.