AquaPro thin film composite reverse osmosis membranes deliver high salt rejection while maintaining high production rates to obtain the energy efficiency demanded by plant operators. By selecting the highest grade of materials and thoroughly testing performance, Racor Village Marine is able to offer the highest quality products.Aqua Pro membranes are designed for use in Racor Village Marine pressure vessel housings as well as other brand housings. Maximum Operating Pressure: 1000 psi Maximum Operating Temperature: 113F (45C) Maximum Feed Turbidity: 1 NTU Free Chlorine Tolerance: 0 PPM Maximum Feed Silt Density Index: SDI 5 pH Range: Continuous Operation: 4-11 Short-term for Cleaning: (30 minute duration) 2.5-11Model 12791745 is for DC Voltage units with one membrane. Model 12791737 is for DC Voltage units with two membranes.