The FROG® @ease® system, designed specifically for your Bullfrog Spa®* offers a self-regulating water care experience that is easier than ever. SmartChlor® technology uses up to 75% less chlorine, maintains chlorine at lower levels, & reduces the frequent need for hot tub maintenance. Use this cartridge holder to convert your 2-filter spa to the FROG® @ease® for Bullfrog Spas® water care system.