OWC Internal SSD DIY Kit for Apple iMac 27" OWCDIDIM27SSD11 B&H
Amazon.com: USB C Hub for iMac 24 inch 2021, Minisopuru USB Hub Adapter Support M.2 NVMe SSD, iMac USB Hub, 7 in 1 iMac Accessories with USB C 10Gbps, USB A 3.2,
How can i choose to boot from the second SSD harddisk for a mid 2011 iMac? - Ask Different
SSD Upgrades for Apple iMac 27-Inch Late 2013 - 2019