4.0Mm Min Bore Guhring Boring/Profiling Rh System 104 Insert, 0.30Mm (T-Max) Offset, 12Mm Reach, Uncoated Right Hand, 0.25Mm Radius, Bright Uncoated Gt104.2037.025.12.40.R, Uncoated Type Gt104 Guhring Micro-Precision System 104 Carbide Stick Insert With 4Mm Quick Change Shank For Boring & Profiling. Guhring Series No. 25080 Order Code 4.023 Made In Germany, Guhring Part #9250800040230 Guhring Inc.