HIGH QUALITY MATERIALOur spa mineral sticks are made of high quality and healthy ABS material, odorless and fine workmanship. Drops 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 out a variety of impurities, keeping spa water in good quality and keeping your bathtub clean. EASY TO USE AND REPLACE Simply place the parts of the Mineral stick in your spa filter or skimmer basket and let them do their job, no other complicated process needed. 2 practical parts to be replaced in time. (Recommended to replace once every 3-4 months.) LOW MAINTENANCEWith our spa filter cartridge, can provide up to 4 months of service for your spa filter, and the maintenance cost is extremely low, helpful to save your time and cost, you won't have to check or change it for the next four months. WIDELY APPLICABLEThese spa cartridges suitable for most spas and hot tubs, also compatible with inflatable spas, hot tubs, walk-in tubs, outdoor pools, baths, plunge pools and the easiest to use standard tubs.