4GB (1X4GB) Mem Ram For ASRock Z370 Pro4, Z370 Killer SLI, by CMS d23 | eBay
OFFTEK 16GB Replacement Memory RAM Upgrade for AsRock Z370 Pro4 (DDR4-21300 (PC4-2666) - Non-ECC) Motherboard Memory at Amazon.com
ASRock > Z370 Extreme4
Asrock Z370 Pro 4 vrm thermal pad replacement. Original pad was 1mm thickness, replaced with 0.5mm thick Gelid Extreme pad. Board doesn't have a temp sensor for the vrm's but cpu does
128GB (4X32GB) Mem Ram For ASRock Z370 Pro4, Z370 Killer SLI, by CMS c144 | eBay