What GPU size does the Intel NUC 9 Ghost Canyon's PCIe x16 slot support?

The Intel NUC 9 Ghost Canyon’s PCIe Gen 3 x16 slot fits a full-height, double-width GPU up to 8 inches long, plus a PCIe x4 slot for additional expansion cards. It’s one of the most expandable NUCs Intel ever made — a rare mini PC that actually accepts a proper desktop graphics card.