For ER20 Series Collets The Entire Clamping Range Is From .039" To .511" CAT Taper Shank Per ASME B5.50-2009-CAT AT3 Or Better Accuracy On Shank Tapers Concentric To 0.0002" T.I.R (At I.D.) AD/B Coolant Supply: Coolant Thru The Spindle & DIN Coolant...