Set 6Pcs Knife Sharpening Stones Polishing Whetstone Oilstone We Ship from Chinadelivery takes 15-25 days Size:100*10*5mm Grit:180#;400#;600#;800#;1000#;1500#; optical glass, carbide, titanium, agate, cylinder liners, bearings steel polishing, sharpening high-speed steel cutting tools;