KAC 600m micrometer sight

[Loner]

I'm fairly new to this sight. How do you go about with the numbers below the sight that you can rotate? And what is the recommended zero for this?

[coldblue]

Both our (KAC) 600 meter models (original and new Micro) are marked for ranges: 200, 300, 400, 500, 600 meters by large raised numbers on the elevation drum.
There are also intermediate clicks between each range number for fine tuning purposes. Basically this dublicates the elevation adjustments on the removealbe carrying handle type rear sight.
What I like most about this sight is its ability to fine tune. Like my dope for 300 meters slow fire sitting is 300 minus 1 click; and then for 300 meter rapid prone it changes to 300 +1 because my spot weld and eye relief changes between those firing positions.
These intermediate clicks also allow the sight to adapt to different barrel lengths, sight radious, and calibers. One just needs to dope out their weapon combination over known distance ranges, like we do in the Marine Corps during requalification, and record your dope accordingly.
I start my zeroing at 50 meters with the sight's elevation set to "2."
Then depending on barrel length and length of sight radius I fine tune at 200.