HIGH QUALITY MATERIALOur spa mineral sticks are made of high quality and healthy ABS material, no odor and fine workmanship. Directly fall into the spa filter, keep the water fresh and clear for a long time, bring you a natural and healthy spa. EXCELLENT FILTRATION SYSTEMMulti-layer filtration of the spa mineral filter makes water healthier and can effectively filter a variety of impurities, keeping spa water in good quality and keeping your tub clean. EASY TO USE AND REPLACESimply place the mineral stick parts into your spa filter or skimmer basket and let them do their job, no other complicated process is needed. 2 pieces convenient for you to replace on time. (Recommended to replace it 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 are suitable for most spas and hot tubs, also compatible with inflatable spas, hot tubs, walk-in tubs, outdoor pools, baths, plunge pools and standard bathtubs, most easy to use. Delivery quantity: 2 pieces (yellow)