Cable Plus HDD SSD SATA Hard Drive Connector for MacBook Pro Unibody 13" A1278 MacBookPro7,1 Mid 2010: MC374LL/A MC375LL/A laptop-computer-replacement-parts - Walmart.com
OWC SSD
MacBook Pro Repair - iFixit
Best Buy: Apple MacBook Pro 13" Display with Touch Bar Intel Core i5 8GB Memory 256GB SSD Space Gray MXK32LL/A
Apple MacBook Pro A1398 Laptop i7-4980HQ 2.80GHz 500GB SSD 16GB RAM 15.4" NO OS | eBay
HDD Caddy for Macbook Pro 13, 15, 17 inch Unibody
Identify your MacBook Pro model – Apple Support (UK)