If you're looking for an easy and hassle-free way to keep your hot tub sanitized, look no further than the FROG Serene Replacement Cartridges. Designed for use in the FROG Serene In-Line System or FROG Serene Floating System

FEATURES:

• Pre-filled replacement cartridges for no mess, no guess and no stress water care!
• Mineral Cartridge lasts 4 months.
• Bromine Cartridge lasts 2-4 weeks.
• Bromine Cartridges are recyclable when empty.