Nauticam handle screw size

Hi all, 

I don't have the housing with me and I need a quick info.

What's the diameter of the hex screw on the Nauticam handle? M8, M10?

See the attachment 

Mine are M10, but there might be more than one size

BVA
 

Thanks Bill,

I saw Locline type arms directly attached to the Nauticam handles. It should be a custom solution.

My Olympus housing has M8- metric threads are easy just place a ruler up against the bolt on the threaded end, M8 is 8mm diameter (actually 7.97 - but it's definitely not 9.9mm).