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? Do PRS SE’s have real maple tops? What is the difference between a "10 Top" and an "Artist Grade" ? Year Identification What are the differences in TAP, SPLIT, and ISOLATED SPLIT Pickups?