The 6 inch brackets are used for the ear opening on a deers ear. The 12 inch brackets are used from nose to the back of the head. The 24 inch bracket (thick horizontal post to thick horizontal post) is used to bracket the front leg and the back leg.
Another way to look at it-- from the middle vertical crosswire to the first hash mark = 6 inches
From the middle vertical wire to the thick wire is 12 inches.
From the first hash mark on the left or right to the thick wire on the opposite side is 18 inches.
All together they make 24 inches. thick wire to thick wire.
Your yardage marks are shown in the illustration above. They go 20-30-40 and 50.
Please: Everyone that doesn't understand any of this, ask questions. I think this is one of the best rangefinding systems out there and want everyone to understand how to use it.
Here is a pic I made up to help a little. These marks are to show the orientation of the 6,12,18 and 24 inch reference points. They are 6,12,18 and 24 inches at ANY given yardage. Just move them up and down the marks to see what yardage you are at.
Light red to light red is 6 inches.
Blue to blue is 12 inches.
Yellow to yellow is 18 inches.
Green to Green is 24 inches.
So if we take the green to green and move it up to the 20 yard lines-- it would be the outer dark line to the outer dark line. That would be 24 inches at 20 yards. Is anyone understanding this? Ask lots of questions, I'll try to help.