These bits feature a thin rim turbo segment for precise and fast drilling of most tiles and hard stone. The bit has a built in 12" shank and a removable pilot bit. Best used in a hand held cordless drill. Note: When drilling hard and brittle materials like tile and stone, remove the pilot bit because it could crack the material. Instead make a template out of cardboard and start the hole. Once the hole has been started, remove the template and continue drilling.