4.0Mm Min Bore Guhring Boring/Profiling Lh System 104 Insert, 0.60Mm (T-Max) Offset, 17Mm Reach, Uncoated Left Hand, 0.25Mm Radius, Bright Uncoated Gt104.4737.025.17.40.L, Uncoated Type Gt104 Guhring Micro-Precision System 104 Carbide Stick Insert With 4Mm Quick Change Shank For Boring & Profiling. Guhring Series No. 25073 Order Code 4.036 Made In Germany, Guhring Part #9250730040360 Guhring Inc.