Diameter range: 16-100 mm hole core drill bit opener for ceramic and glass; can cut holes within this range with precise results. Includes center drill bit 22 mm to start the hole accurately, improving alignment and drilling efficiency. Specifically engineered for ceramic and glass materials; delivers clean, smooth holes with minimal surface damage. One-piece design for easy use and compact storage; simplifies drilling and reduces the need for multiple tools. Made from high quality materials; durable and long-lasting even under frequent or demanding ceramic and glass drilling tasks. Use scenarios - Installing fixtures or piping through ceramic wall or floor tiles during renovations. - Drilling glass panels for shelves, display cases, or decorative installations. - Performing precise openings in ceramic or glass surfaces for cabinetry, countertops, or window projects.