I Installed SSD on a Lenovo ThinkCentre M800 (using this Hack) - YouTube
Lenovo ThinkCentre M800 Small Form Factor PC Intel Quad Core i5 6500 up to 3.6GHz 16G DDR4 240G SSD 2T HDD WIFI BT 4.0 DVD Win 10 Pro 64-Multi-Language Support English/Spanish/FrenchRenewed Minis
ThinkCenter M800 SFF | Compact Enterprise Desktop | Lenovo UK
Lenovo ThinkCentre M800 SFF G4400 3.3GHz 8GB 500GB HDD BN Windows 10 Home | Computers \ Case \ Small Form Factor SFF | AMSO
Lenovo ThinkCentre M800 Small Form Factor Desktop 10FY0013US B&H