I did it. I bought an box adapter (2.53 -> 3.5") but it's only to fix it mechanically in the iMac, no need for a plug adapter. Some even does it with tape.... Anyway it's great to have a SSD ! only bug, I taped back (wrongly ?) the thermal sensor on it, and the SSD temperature is now saying always 128° (iStat Menu). But the fan turns at 1300rpm. Nothing to worry about.