Select Face Ring
Selects a face ring from each selected face.
ProBuilder only considers faces part of a ring if they are quads (contain exactly four sides). Face rings generally run along the X-axis, whereas face loops generally run along the Z-axis.
This action is available only in face mode.
You can use this tool with the Alt/Opt+R shortcut, or from the ProBuilder menu (Tools > ProBuilder > Selection > Select Ring).