What does the 594 mean in the PRS McCarty 594 and PRS McCarty SC 594? January 24, 2022 19:15 Updated What does the 594 mean in the PRS McCarty 594 and PRS McCarty SC 594? These guitars get their names from the scale length, which is 24.594”. Related articles Is the scale length different on a PRS Custom 22 guitar versus a PRS Custom 24 guitar? What is the difference between a "10 Top" and an "Artist Grade" ? Do PRS SE’s have real maple tops? Neck Profiles What is a 10 top?