Collis Tool 68927 Adjustable Spindle Extension Assemblies; Shank Thread Size: 1-1/16 - 12 ; Morse Taper Size: 3MT ; Shank Length (Inch): 3-5/8 ; Flange Thickness (Inch): 3/8 ; Extension Diameter (Inch): 1-5/16 ; Extension Diameter (Decimal Inch): 1.3