I read some bad reviews and for some reason I expected a better experience. Unfortunately I ran to the hardware store a few minutes after trying these things out. A quarter inch bit couldn't go through a tile until the entire diamond was worn away. I had to drill 6 holes and this drill bit did 1/2. I bought a similar nozzle in Milwaukee and it worked. The cost per bit is higher than this hole but it really worked. Stay away from them.