Step 1: Under the Tap Adapter tab, select the proper Adapter Size show Adapter Size Dimensions
Step 2: Select the proper tap size (There are 2 ways to narrow results)
By Tap Size - You may select the proper tap size if you are using an ANSI tap
-or-
By Tap Dimensions - a certain way to find the proper tap size if you know the Tap Dimensions or if you have an existing Tap to measure
You may select inch or metric Tap Dimensions from the drop downs