The FloraFlex? Matrix Pad is part of the Matrix System, a patent-pending first-of-its-kind Top Feeding Wicking System that provides the most even way to deliver water and nutrients to your potted plants. It can be used with the PotPro System, Rockwool cubes, or any other container you desire to use them with. The Matrix was not designed to be suspended above, but rather directly on top of, or touching the medium. You will need a Matrix unit, the same size Matrix Pad (optional), and the 2-1/4 inch Matrix Circulator.