Hydronix BW-4040 Hydron High Performance Commercial and Industrial Membrane, 2400 GPD, 40" x 4" Hydron 2400 Gallon per day Commercial Membrane Fits standard 4x40 Commercial RO membrane housings 2,400 GPD, 99.0% rejection and a minimum rejection rate of 98.5% Hard fiberglass shell protects membrane and provides outstanding performance Made in Taiwan