EXTREME TYPHOON III 150 GPD RODI with Gauge & TDS Alarm & Dual TDS Meter TW301812-150 Membrane produces up to 6.25 gallons per hour or 150 gallons per day.* (Stage 4) Full size Color Changing mixed bed D.I. using Resin Tech DI resin. This is a refillable Di cartridge One micron pre-filter array (1-3) of the five stages.