So Dan, just to make sure, here is my situation. I have a 2011 21.5 inch iMac. It had a 3.5inch 500GB hard drive, which died. I plan on fixing the machine, but I am somewhat on a budget. If I get a normal hard drive or hybrid drive (SSHD) then I should get the OWC cable with it, because Hard drives generate a decent amount of heat. However, if I replace the broken Hard Drive with an SSD and used a 2.5-3.5inch adaptor, then I wouldn’t necessarily need the OWC thermal sensor because SSDs (especially just a 500GB one that I am replacing) don’t run as hot as normal HDDs. So because of that, I can get away with using a short block or using the Y adaptor, because that is what even Apple used (right?) Thanks!