HIGH QUALITY MATERIALOur spa mineral sticks are made of high quality and healthy ABS material, no odor and fine workmanship. Drip directly into the spa filter to keep the water fresh and clear for a long time, giving you a natural and healthy spa treatment. Excellent Filtration SystemMulti-layer filtration of spa mineral filter makes the water healthier, can effectively filter various impurities, maintain high-quality spa water and keep the bathtub clean. Easy to use and replaceJust drop the mineral rod parts into your spa filter or separator basket and let them do the job, no other complicated process required. 2 Practical parts should be replaced in time. (It is recommended to replace every 3-4 months.)Low MaintenanceUse our spa filter cartridges to service your spa filter for up to 4 months with very low maintenance costs, helping to save you time and cost, you won't have to inspect or replace for the next four months. Wide ApplicableThese spa cartridges are suitable for most spas and hot tubs, and are also compatible with the easiest to use inflatable spas, hot tubs, walk-in tubs, outdoor pools, tubs, plunge pools and standard tubs.