Heavy DutyNEW CYLINDER ENGINE HONE KIT 2-1/2" TO 5-1/2" (63MM TO 137MM) HONING MACHINE WITH12 SETS OF MULTI GRIT SILICON CARBIDE Stones (VITRIFIED BOND) 320 EXTRA FINE (3x Sets)220 FINE (3x Sets)180 MEDIUM (3x Sets)120 COARSE (3x Sets) COMPLETE HONING MACHINE - HONE KIT SIZE – 2-1/2" TO 5-1/2" (63MM TO 137MM) STONES –Coarse 120 (3 SET = 12 STONES)Medium 180 (3 SET = 12 STONES)Fine 220 (3 SET = 12 STONES)Super Fine 320 (3 SET = 12 STONES)