Thermaltake Core P1 mATX / micro-ATX PCIe Card Bracket Adapter

thingiverse

Despite its design limitations, it's surprisingly easy to fit an mATX board into the Termaltake Core P1 case - just be prepared for the fact that it'll be secured by only four screws. To accommodate a graphics or extension card in one of the lower PCI(e) slots, you'll need to swap out the standard 2-slot back panel for a longer version that offers 4-5 slots. I've found that adding M3 sink nuts works beautifully, especially when fitted with a soldering iron; however, a screw and nut setup should also suffice.