[High-quality sponge material] Traditional sponge balls have large pores and are prone to yellowing. The upgraded spa hot tub descaling balls are made of high-quality sponge material with a whisker-like texture. This improved sponge effectively removes dirt, body oil, foam, and other residues, absorbs fine impurities to the maximum extent, and is resistant to yellowing and shedding, helping keep your pool or hot tub clean and well-maintained. [Absorbs grease and all dirt] These spa hot tub descaling balls can absorb more than 41 times their own weight in inanimate dirt. Through capillary action and surface tension, these reusable descaling balls efficiently absorb and remove grease, debris, pollen, and other contaminants from swimming pools, hot tubs, and spas. [Elastic and reusable] The upgraded sponge material captures pollutants without dissolving. The oil-absorbing sponge balls are washable and flexible. After use, simply squeeze out the water and rinse the balls; they quickly regain their shape and are ready for reuse, offering a cost-effective and time-saving cleaning solution for any pool or hot tub owner. [Easy to Use] Just place the scum balls into your pool or hot tub. Their unique floating design allows them to move freely, cleaning all surfaces automatically. When saturated, simply squeeze out the absorbed oils, rinse the sponge, and return it to the water for continued use. [Gentle Cleaning] Unlike traditional pool chemicals, these floating filter balls remove dirt through physical absorption, requiring no harsh chemicals. This provides an environmentally friendly way to maintain clear, clean water in pools, hot tubs, and spas without risk to users. Color: White Material: Sponge Size: Approximately 3 inches Package Contents: 8 x Hot Tub Cleaner Balls Note: Light reflection and differences in display screens may cause slight variations between the color of the item in the image and the actual product. Measurement may vary by +/- 1-3 cm.