OWC Tears Down iMac Retina 4K, Confirms Memory Is Soldered
iMac Intel 21.5" and 27" (Late 2009-Mid 2010) SSD Upgrade Bundle - iFixit Store
Original 512GB SSD MZ-JPU512T/0A6 For Apple iMac 21.5-inch A1418 Retina(Late 2013 – Late 2015), iMac 27-inch A1419 Retina(Late 2013 – Late 2015), Mac mini (Late 2014), Mac Pro (Late 2013), MacBook Air