This thermowell allows for protection of your thermometer probe within your kettle while still allowing an accurate temperature read. Fits into a 1/2" coupling on the outside of your kettle while allowing a 1/2 MPT thermometer to thread into the Female pipe thread on the outside. Will Work with Thermometers up to 3" in length. For the most accurate reading, we recommend using a thermal grease inside the thermowell to fill the space between the thermometer and the inner walls of the thermowell.