diamond core bits 12mm 1.Fast and Smooth cutting 2.Long lifetime 3.No Chipping 4.Minimizing any breakage diamond core bits 12mm Company Advantage:1.Over 10 years experience 2.ISO9001-2000 certificate 3.OEM Accepted.4.Experienced of Fair: USA Coverings, Russia Stone Fair etc.Specification:1.Center water fed.2.Diameter:3/16''(5mm), 1/4'' , 5/16'' , 3/8'' , 1/2''(12mm) etc.4.Connection:5/8''- ...