These are really good Diamond holesaws.

Material Diamond
Brand Diintor
Colour Silver
Compatible material Ceramic, Marble, Stone
About this item
❤This product uses advanced natural diamond material, with a special enhanced coagulation treatment from electroplating sand suction hole neat, smooth, no broken edges, etc., is the efficient construction, installation hole of choice。
❤Outside Diameter:100mm; Hex Shank Diameter:10 mm (3/8"); Total length:65mm; Drill depth:29-30mm。
❤Easy to use, high quality,good performance, long life - Excellent for making clean and accurate hol 。
❤Excellent for making clean and accurate hole on glass, tile, granite and marble 。
❤Do NOT run dry. Diamond Coated Tools will work best if you use water to keep the tools cool。