VONTRON -ULP1812-75 Thin-Film Composite (TFC) RO Membrane. KEY FEATURES This membrane is tested and certified under NSF/ANSI Standard 58 for material requirement. VONTRON TFC Reverse Osmosis Membranes are made of the good quality spiral-wound Poly-amide and offer outstanding pollutant rejection at water pressures up to 125 psi. You can use UP till 3 years of intervals or sooner only if TDS levels increase beyond normal levels. 75 GPD (Gallons per Day) production capacity. Standard size fits most 4 and 5 stage residential RO systems with flow restrictions rated at 80 gallons per day. Flow Rates and Production Capacity. Membrane Type: Thin-Film Composite (TFC). Diameter: 1.8 Inch. Length: 11.75 Inch Outside. Membrane Material: Poly-amide (PA). Element Configuration: Spiral Wound. Maximum Operating Pressure: 125 psi. Maximum Operating Temperature: 113 Degrees F (45 Degrees C). Operating pH Range: 3.0-10.0. Fits all standard 2 Inch x 12 Inch RO membrane housings.