Piranha PAVBDB HEX 1/4" Diamond Core Bit – Hex Shaft Coring Bit for Porcelain & Marble kerdi-kereck which is exactly what you

which is exactly what you need for a single bench that meets one wall

Attached acoustic underlayment — reduces hollow sound and adds warmth underfoot

so it expands and contracts at the same rate

It's especially good for bathrooms

Piranha PAVBDB HEX 1/4" Diamond Core Bit – Hex Shaft Coring Bit for Porcelain & Marble kerdi-kereck which is exactly what youThe Piranha PAVBDB HEX 1 4" coring bit is a vacuum brazed diamond core bit built for clean, accurate holes in porcelain, marble, and stone. Its hexagonal shaft chucks directly into a standard drill, so you don't need a grinder or threaded adapter to get started. The combination of vacuum brazing and synthetic diamond helps the bit regulate heat for consistent cutting quality and a durable diamond to bit bond. Suitable for both wet and dry use, though