This mount is for Colnago C68 V4Rs C64 V3Rs seat post, allowing you to mount any accessory with a gopro mount
And following fastener2 x M3x5mm1 x M4x16mm
Update V2:A new version is now available, the V2 has been optimized for FDM printing, you can print it without supports.
3D PRINTING SETTINGS
I suggest printing this in nylon fiber with carbon or something similar.
Use 0.2mm layer height with at least 50% infill