To properly measure for your custom fit Radio Belt you will need a flexible tape measurer, a piece of webbing or if you have access to one a radio belt.
Measuring with a radio belt: If you have access to a radio belt. Put it on andadjust the belt to how you like to wear it. When you are happy with your adjustment, take the tape measurer and place it on the front side of the belt at the point where the leather wraps around the snap.
Take the running end and drape it over your shoulder following the radio belt. Your end measurement will be at the point where the leather wraps around the snap. This will be your belt length.
For the shoulder mic, determine the location where you like to wear your shoulder mic and then measure from the same starting point on the front of the radio belt to the center point of the shoulder mic. This will be your shoulder mic measurement.