Amazon.com: GODSHARK 7+17 pin mSATA to A1398 A1425 (2012 & Early 2013) Adapter for MacBook Pro Retina SSD Replacement, Mini PCIe SATA SSD Converter Card : Electronics
Configure your own 13-inch Apple MacBook Pro (2012) at OWC
Mid-2012 Macbook Pro (SSD) Hard Drive Upgrade How To - YouTube
A1278, A1286, A1297, HDD, Hard Drive replacment,
2TB MacBook Pro Hard Drive A1278 A1286 A1297 replacement
Fix Apple MacBook Pro A1278 Mid 2012 hard drive cable - flashing question mark folder, HDD missing - YouTube
Installing MacBook Pro 13" Unibody Mid 2012 Dual Hard Drive - iFixit Repair Guide
Amazon.com: HIGHFINE 2nd 2.5'' SATA HDD SSD Hard Drive Disk DVD CD ROM Optical SuperDrive Caddy Tray Adapter for Apple Unibody MacBook/MacBook Pro 13 15 17 Early mid Late 2008 2009 2010 2011 2012.etc : Electronics
macbook pro mid 2012 hard drive upgrade to SSD SATA recommendation - Ask Different
Installing MacBook Pro 15" Unibody Mid 2012 Dual Hard Drive - iFixit Repair Guide
922-9032) Optical Drive SATA Cable – Apple MacBook Pro 15″ (Mid 2009, Mid 2010, Early 2011, Late 2011, Mid 2012)
SATA III hard drives may not work with older MacBooks. Here's why | Macworld
After 2 years of using a mid 2012 Macbook Pro, I did the upgrade! : r/ macbook