The FloraFlex® Matrix Circulator 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 plants. It can be used with pots ranging from 7.5-18 inch diameters. You will need a Matrix unit, the same size Matrix Pad, and the correlating Matrix Circulator. Water and the nutrients travel into the Circulator, hit the slope of the Matrix and are pushed outward into eight maze sections that have individual holes dripping the water and nutrients onto the Wicking Pad. The Circulator has two barbed nozzles to attach 1/4 inch OD FloraTubing that allows you to automate the Matrix System. Use the 2-1/4 inch Circulator with the 7.5 and 9 inch Matrix. Use the 3 inch Circulator with the 10.5, 12.5, and 15.5 inch Matrix. Place the Matrix Pad on the surface of your plant, the Matrix Unit on top of it, press down, fit the Circulator into the center holes, and connect your 1/4 inch OD tubing to the Circulator.