The Pentair Pentek TLC-100 is a Thin Layer Composite (TLC) reverse osmosis membrane element that delivers high-quality water across a broad range of water chemistries. Through reverse osmosis it reduces total dissolved solids and a wide range of dissolved impurities, supporting cleaner, better-tasting drinking water. Each membrane is tested to the factory's performance requirements before shipment, and the 100% dry construction is designed to maximize shelf life before installation. The TLC-100 produces up to 100 gallons per day (378 LPD) with 97% nominal rejection, rated on 500 ppm softened tap water at 65 psig and 77 degrees F at 15% recovery. It maintains high rejection stability even at high input TDS. The TLC membrane series is tested and certified by NSF International against NSF/ANSI Standard 58 for material safety and the reduction of arsenic, barium, cadmium, chromium (hexavalent and trivalent), copper, turbidity, fluoride, lead, radium 226/228, selenium, and TDS. With standard dimensions of 1.83 inches in diameter and 11.75 inches in length (4.65 cm x 29.85 cm), the TLC-100 fits commonly available reverse osmosis housings as a replacement element. Operational limits are a maximum pressure of 125 psi (6.90 bar), a maximum temperature of 120 degrees F (49 degrees C), and a pH range of 4 to 11. Because the membrane tolerates only 0.1 ppm free chlorine, install a carbon prefilter ahead of it to protect the membrane and extend its service life.