FROG @Ease Floating Sanitizing System for Hot Tubs, Quick and Easy Self-Regulating Hot Tub Sanitizer with Sanitizing Minerals and SmartChlor TechnologyBrand: FROG Color: Blue Features: Kills bacteria 2 ways with a low level of chlorine and FROG Sanitizing Minerals. Minerals last 4 months, SmartChlor lasts up to 4 weeks depending on hot tub size and use; floats when working, flips when empty, ideally for hot tubs up to 600 gallons FROG @ease uses SmartChlor, a patented chlorine formula that adds a low level of chlorine only when needed. Combined with FROG Sanitizing Minerals, FROG @ease creates Fresh