High Quality Material The spa mineral stick is made of high quality and healthy ABS materials, odorless and fine workmanship. Drops into the spa filter directly, 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 water more healthy and can effectively filter out a variety of impurities, keeping spa water of good quality and keeping your tub clean. Easy to use and replace Simply place this mineral stick into your spa filter. spa or your skimmer basket and let them do their job, no other complicated process is needed. (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 cost of maintenance 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 applicable Suitable for most spas and hot tubs whirlpool, also compatible with inflatable spas, hot tubs, walk-in tubs, outdoor pools, thermal pools, baths, plunge pools and the easiest to use standard tubs.