[@mmc_jake]

To the best of my knowledge, there is no metric standard for camera mounts. The international standard ISO 1222 specifies 1/4″-20 UNC or 3/8-16 UNC for tripod threads, which translates to a wide range of cost-effective adapters that are available all over the world.

If you would feel like there is another standard mounting adapter/interface that should be included, feel free to suggest it.