MATERIALOur spa mineral sticks are made of healthy and ABS materials, no odor and fine workmanship. Falls directly into the spa filter, keeps the water fresh and clear for a long time, brings you a natural and healthy spa. EXCELLENT FILTRATION SYSTEM The multi-layer filtration of the spa mineral filter makes the healthier water and can effectively filter a variety of impurities, keeping the spa water of and keeping your bathtub clean. EASY TO USE AND REPLACESimply place the parts of the mineral stick into your spa filter or skimmer basket and let them do their job, no other complicated processes needed. 2 practical parts to replace in time. (Recommended to replace it once every 3-4 months.) LOW MAINTENANCE With our spa filter cartridge, can provide up to 4 months service for your spa filter, and the maintenance cost is extremely low, helpful to save your time and cost, you wont have to check or change it for the next four months. WIDELY APPLICABLE These spa cartridges suitable for most spas and hot tubs, also compatible with inflatable spas, jacuzzis, walk-in bathtubs, outdoor swimming pools, baths, plunge pools and most easy-to-use standard bathtubs. Quantity delivered: 2 pieces luckymeet