Install a second 2.5" SATA hard drive in your iMac.
Increase the storage space in your computer by replacing the optical drive with a second SATA hard drive or SSD.
Replace a broken or damaged power supply compatible with an iMac 27" Intel (Late 2009 to Mid 2011).
Install an additional 2.5" SATA hard drive in your Mid 2011 27" iMac.
Connect an optical drive to your computer via USB with this part.