Mounting plate comes with the Model WB. You attach the mounting plate to the floor with 4 screws, then the toilet fits down over pins on the plate. Cushioning pads protect the toilet from vibration. You need a mounting plate for marine or mobile applications, so it is included with the Model WB. In a house, the mounting plate is NOT needed. Because of the cushioning pads, it will feel a little “rocky” when you sit on it. You can remove the pads if you feel you really need to mount the toilet.