Cyclus head tube reamer

The new designation system (S.H.I.S. - Standardized Headset Identification System) was used for the designation of the individual milling cutters. It consists of the type of headset and the corresponding inner diameter of the head tube (e.g. EC 34). EC (External Cup) stands for the classic headset, ZS (Zero Stack) for the half integrated headset and IS (Integrated Standard) for the integrated headset.