Aquarion® Fluid Cartridges, Gravity-Fed, 3.7 gal. Capacity, Meets ANSI Z358.1Pair Sealed and ready to use cartridges ensure safe, pure, contaminant free flushing fluid for 2 years Self evacuating cartridges store the fluid and help maintain a required flow throughout the entire 15 minute flush without any external force Actuation is a simple, one step processjust pull the tray down in an easy motion and the fluid begins to flow in less than a second Sealed Fluid Cartridges Sterile Saline Solution 3. 7 Gal (14 L) per cartridge