1.00Mm Width, 4.0Mm Min Bore, Guhring Lh Straight Groove I.D. System 104 Insert, 12Mm Reach, Nano-A Coated 1.00Mm Width, 1.00Mm Depth, 12Mm Reach Ge104.0100.000.12.40.L, Nano-A Coated Type Ge104 Guhring Micro-Precision System 104 Carbide Stick Insert With 4Mm Quick Change Shank For Internal Grooving Straight Slots. Guhring Series No. 25127 Order Code 4.019 Made In Germany, Guhring Part #9251270040190 Guhring Inc.