Maximum Individual Spacing Error: 25 seconds Vernier Reading:10 seconds Base to Chuck Squareness(90'): 0.0008" *For milling, drilling, jig boring, and many common shop applications*24 position hardened and ground index plate(15' increments) with satin chrome dial,360ºgraduated ring and adjustable 10 second vernier *Each unit is equipped with six(6) masking plates(2,3,4,6,8, 12and 24 divisions) ...