This NSK attachment for Electer Emax and Rotus systems is ideal for chamfering small interior small interior cross-holes.• Minimum Inner Diameter: ø0.79"• Weight : 1.76 oz.• Collet Chuck Standard Size : ø1.6 mm (K-252)• NSK Catalog Number: RE10247Included Equipment:• Collet Chuck ø1.6 mm (K-252): 1 pc.• Chuck Wrench (K-232): 1 pc. each • Pin Wrench (K-233) : 1 pc.