Made a template out of plywood to allow these drills to work accurately as they don't have a center drill and I couldn't find a diamond saw hole the size they did. I made a 4.5" hole with a 4.5" wood hole saw for my temporary valve and a 2.5" hole with a 2.5" wood hole saw for my gear value (measured and aligned of course ). The piece of plywood was exactly the same size as the tile. I carefully placed the plywood on top of the tile, filled the two holes with water to cool it, and started drilling at high speed with the Makita cordless tool. I had two perfect holes in just over a minute and didn't have to hope and pray like I did with an angle grinder. The tile looks like it came from the factory with those very precisely cut holes. None of the ugly, uneven (even if you don't see it) bullshit you often see. The smaller and more precise the hole, the less likely water is to get where it needs to go.