3.0Mm Min Bore Guhring Boring/Profiling Lh System 104 Insert, .015Mm (T-Max) Offset, 12Mm Reach, Uncoated Left Hand, 0.20Mm Radius, Bright Uncoated Gt104.0827.020.12.30.L, Uncoated Type Gt104 Guhring Micro-Precision System 104 Carbide Stick Insert With 4Mm Quick Change Shank For Boring & Profiling. Guhring Series No. 25089 Order Code 4.010 Made In Germany, Guhring Part #9250890040100 Guhring Inc.