Please check the product pictures for the size references
For the measurements, take a string and wrap it around the root of your boner or behind your balls. Mark the string where it meets. Make sure that you should be able to fit a finger between your skin and the string when your little boy is soft. This method can help you to achieve a comfortable tight when you are hard. Measure the length of the string and this is the circumference. Use our measurement chart the get your size.