Antec HCP Platinum Dual 8 Pin to Nvidia RTX30 12 Pin PCIE Modular Cable - MODDIY
Nvidia's 12-pin power connector for next-gen GeForce cards makes a lot of sense when you see it | PCWorld
Amazon.com: COMeap Replaement for Dual PCIe 8 Pin Male to Mini 12 Pin NVIDIA GeForce RTX 30 Series GPU Power Adapter Cable for EVGA Seasonic Modular PSUs 25-inch(63cm) : Electronics
Pinout for 12-pin adapter included with RTX 3080 : r/nvidia