[Safe Material] These well-designed spa mineral rods are made of high-quality ABS plastic and are sturdy and odorless. The minerals they contain will not cause any harm to the human body, so feel free to use them. The mineral inside the spa mineral rod can effectively absorb some impurities in the water, creating a better and safer aquatic environment for you to enjoy your spa. Features: Easy to Install * Hot spring mineral rods are not affected by heat and can be installed on your existing stream. Simply place the spa rod into the existing filter and let the new rod do its work. Natural Mineral Substance * Ensures your spa is odor-free, improves spa performance, and provides you with crystal-clear, clean, and fresh water without harmful chemicals. Fits Most Spas and Hot Tubs * Suitable for hot tubs, inflatable tubs, niche tubs, walk-in tubs, whirlpool tubs, spa boats, and the easiest standard tubs to use, taking only seconds to install. Ideal Choice * Our hot tub rod spa can hold up