... range of sizes Diamond core drill bits for concrete,wall,floor,masonry, dry use 1, Suitable in Asia, Russia, Middle east ... ;4, Available diameters from 10mm to 800mm.5, Available effective working length 380mm, 400mm, 450mm, 500mm, extra long up to 1500mm ... the adaptor size and concentricity by the most advanced inspection equipment from South Korea.Packaged by paper box, carton, plywood case ...