The m.2 standoff size for the Asus Z170-P D3 is 0.35 inches.
The m.2 standoff size for the Asus Z170-P D3 is 0.35 inches.
Hi, I understand your situation with the Asus Z170-P D3. Since it lacks a M.2 standoff, you can't use the NVMe drive you tried. Could you confirm the exact height and diameter of the motherboard you're considering? That will help determine the correct size for installation.
These are likely NVMe SATA mounting screws for a standoff mount.