iMac 27 inch Mid 2010 has an additional SSD BTO. You can have one 3.5 inch Hard drive, one optical drive, and one 2.5 inch SSD, however you can have an additional SSD!
Apple did not include a mounter for SSD with non-SSD model, so you cannot add an SSD since it has nowhere to mount.
Internal SSD installation kit for iMac 27 inch Mid 2010.
1. SSD mounter with pressure plate (Apple genuine part)
2. SATA data cable
3. Y spirit power cable
4. Mount screws (4 pcs)
5. Installation Manual
Installation is not easy. Expert skills are required. Manual is written for experts, so it is not step by step instructions. If you can disassemble an iMac completely, you can do it.