Accessories and replacements parts for Park Tool head and steerer tube cutting tools.Reams head tube I.D. to 43.95mm to accept "internal" headset cups with 44.05 - 44.10mm O.D. (1-1/8 ZS standard)Use the 788 with the 690-XL Facing Cutter and 750 Centering ConeFor upper or lower headtubes that accept the ZS44 or EC44 headsets Park Tool Cutting Tool Accessories Head & Steerer Tube Cutting Tool UPC: 763477013910