How to determine what size Scalar wrist band you need:

Using a sewing tape measure, place the end of the tape measure on the inside of your wrist and wrap it around your wrist. See the below picture to determine the size that is closest to your need.

Using a ruler, place the ruler on the top of your wrist. Take that number multiply it by 2 and then add 2” (2 inches) Example: 2.5” X 2.5” + 2” = 7”. See the below picture to determine the size that is closest to your need.