This unit delivers 100 percent sterile saline from a 100 percent sterile delivery system. A built-in alarm sounds when the unit has been activated and again when the required 15-minute flush is completed. Side windows allow for easy checking of the saline cartridge expiration date. Each station comes with a sign mounting bracket tamper seal installation DVD and a 1-year warranty. Sterile Saline Cartridges (#10903) have a 24-month shelf life.