Rifle Scopes Vortex PST 2.5-10 mRad turret knob diameter?

[SRSDriver]

I'm trying to print a dope strip calibrated for a friends 2.5-10 Vortex... To do this, I need to know how many clicks per revolution of the turrett, and what the diameter of the knob is (to the nearest thou if someone has calipers!)....

Thanks in advance if anyone knows!