The BRMGB41818 (part number GB41818) is a standard-duty [Brush Research GB Flex-Hone Tool](0.5.3, 0.5.14) designed for 4-1/8" (105mm) bore diameters BRUSH RESEARCH 4-1/8" 180 Grit Flex Hone - Silicone Carbide BRMGB41818. It features 180-grit silicon carbide abrasives and is commonly used for engine cylinder deglazing, cross-hole deburring, and creating oil-retaining crosshatch finishes [BRM GB41818 FLEX-HONE®, 4.125" (105mm) Bore, 13.5" OAL, 180 Grit, Sili](0.5.3, 0.5.11).