OWC Internal SSD DIY Kit for All Apple 27-inch iMac 2010 Models (tools included) – RamCity.com.au
Amazon.com: OWC SSD Upgrade Bundle for 2012-2019 21.5" iMacs, Mercury Electra 1.0TB 6G SSD, Express 2.5" USB 3.0 HDD Enclosure, Installation Tools and iMac Screen Adhesive Tape Set : Electronics
maxupgrades.com: Dual SSD Drives kit for iMac 27 inch 2012 Models with Blade SSD Module with Heatsink and Power and DATA Cables
OWC DIY Kit for all 2012 - 2019 27" iMac's factory... at MacSales.com
maxupgrades.com: Single SSD Drives kit for iMac 27 inch 2012 Models with SATA Blade SSD Module / Heatsink/ Power Cable and DATA Cables for [SSD + HDD] with iMac Adhesive LCD Tape
SSD Upgrade Kits for 27-Inch iMac (2012 - Early 2013)