I bought a shower door set there. I had to drill 8 holes in the tile and it took about 7-10 minutes to drill each hole in the tile with a helper constantly spraying water to keep the bits cool. I finally switched to the new nozzle after 3 holes and it was still going slow. Finally, on the penultimate hole, I switched to a club I bought at Lowe's. I wish I had done it on the second hole! It took me maybe a minute to drill the last hole! Don't waste money on them. Just go to Lowe's and spend a little more to get what they sell.