Pentair Rainbow 300-19 Off-Line Automatic Pool Chemical Feeder - R171056 Pentair Model: R171056 Automatically sanitizes pools using chlorine or bromine tablets and sticks with a 5 pound capacity Off-line model retrofits into existing equipment plumbing with 1/4 inch feeder hose Features a heavy duty control valve for accurate feed rate adjustments Includes vent valve, lock ring, screen and check ball, flow-through circulation, external dial control and drain valve