20mm Shank With Flat, GUHRING Coolant Through Floating Reamer Holder For ER25 Collets, 84mm Gage Length With 0.08mm radial play to compensate for deviation between cutting tool and workpiece | vibration-free compensation of concentricity and misalignment | with external slotted nut | purchase wrench separately, Guhring Item No. 9049130250000. For non-coolant through the tool applications use standard ER collets. Guhring Series No. 4307 | For coolant through the cutting tool applications use steel sealed ER collets. Guhring Series No. 4175 | Central coolant supply up to 80 bar maximum pressure. Series No. 4098, Order Code 025.0200. Made in Germany, Guhring Part #9040980250200