These are designed to be used with the Blichmann BoilerMaker Brew Kettles for use in a mash tun. Will also work great if you're using whole hops in your boil kettle (for pellet hops, we recommend using the Blichmann HopBlocker). A patent pending button louver design is a hybrid of a perforated false bottom and a slotted manifold to give you the best of BOTH designs! The hole in the top left of our picture is designed for use with the dip tube that is part of every BoilerMaker Kettle. Click on the second picture there to get a better view of how the screen would look setup with the dip tube! Please Note: This false bottom is designed to work with both G1 and G2 models of Blichmann Boilermakers.