This NSK Nakanishi belt drive spindle turns up to 30,000 rpm. Spindle is belt driven with the use of a pulley. CHK Collets ordered seperately. Specifications: • Allowable Motor Speed: 30,000 rpm • Spindle Accuracy: Within 1 µm • Pulley designed for 0.24" (6mm) diameter round belt. • Weight: 7.47 oz. • NSK Catalog Number: AS41087 (NR-302P) Included Equipment: • Chuck Nut (K-265): 1 pc. • Wrench (12 x 14): 2 pcs. • Collet Chuck (CHK) ø1/8" (3.175mm) Optional Equipment: • Collet Chuck (CHK): ø0.5mm~ø6.0mm in 0.1 mm increments and ø3/32", ø1/8", ø1/4" • Chuck Nut (K-265): For Collet Chuck (CHK)| • Metal Saw Arbor (KCH-03): For ø0.24" (I.D.) x ø1.18" (O.D.) • Drill Chuck Arbor (DCH-J0K): For Jacob's Taper No. 0 • Grindstone Arbor (AGM-03): For grinding wheel with I.D. of ø5mm