MR LP-4040 4"x40" Commercial Reverse Osmosis Membrane Element Dow, Filmtec, Axeon, CSM, Hydranautics, Vontron, Compatible Best for Commercial, Car Wash, Whole House Reverse Osmosis Systems, Industrial, ETC. 2600 GPD @110 PSI and 99.7% Salt Rejection. High Quality Toray Brand Membrane Sheets. Best to use with TDS under 2500 ppm. Compatible with most 4" x 40" Membrane housings, including Dow Filmtec TW30-4040, XLE-4040, LE-4040. Also replaces CSM 4040, Vontron ULP-4040, Axeon, Hydranautics, Hydronix, and Others.