*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, 12and24 divisions) Maximum Individual Spacing Error: 25 seconds Vernier Reading:10 seconds Base to Chuck Squareness(90'): 0.0008" Base Parallelism:0.0004" Mounting Flange Concentricity:0.0008" Chuck Concentricity:0.0005" Ordering InformationModelSizeCenterChuck Cent.Wt.(In.)Ht.(In.)Hole (In.)(Lbs.)ISR-665.1001.730105ISR-886.1002.480185