Enhance your hot tub experience with the FROG @ease SmartChlor Cartridge 3 Pack, designed for use with the FROG @ease in-line system. Simply open the cap on your hot tub, snap in the conveniently adjustable cartridges and enjoy weeks of cleaner, clearer, and softer water. SmartChlor technology self-regulates for continuous crystal clear water and uses up to 75% less chlorine.