4.0Mm Min Bore Guhring Boring/Profiling Lh System 104 Insert, 0.30Mm (T-Max) Offset, 22Mm Reach, Nano-A Coated Left Hand, 0.25Mm Radius, Tialn Coated Gt104.2037.025.22.40.L, Nano-A Coated Type Gt104 Guhring Micro-Precision System 104 Carbide Stick Insert With 4Mm Quick Change Shank For Boring & Profiling. Guhring Series No. 25077 Order Code 4.025 Made In Germany, Guhring Part #9250770040250 Guhring Inc.