Flow-Purâ€™s RV-PRO 10,000 is the most user friendly, competitively priced RV softener on the market today! Features a built-in drain line flow restrictor that provides more effective regeneration, increasing capacity by up to 55%. Custom designed flow valve allows regeneration without having to connect or disconnect from the system. High flow rates up to 4 gpm with low pressure drop. Uses common table salt (not included).