Diamond segments 1.High efficiency,SUPER fast drills 2.Durable in use steel cured concrete 4.Pass UKAS ISO&MPA certificates Diamond segments For dry and wet coring in reinforced concrete with very hard aggregate. Also good for granite, marble, tile, glazed brick and other hard base materials with low abrasiveness.QUALITY LEVEL GUARANTEE: GOLD QUALITY FOR OVER 28METERS CUTTING LIFE, SILVER QUALITY ...