6.2 mm according to the technical data sheet:
https://static.digitecgalaxus.ch/Files...

"Unfortunately, I couldn't find this information anywhere at the manufacturer's or on the web in general. But with a bit of luck, someone else will respond to your question."

I didn't really find anything on the data sheet either.
https://static.digitecgalaxus.ch/Files...

Sorry I couldn't help.