【Pool Filter Balls】Each filter ball is 50m at diameter. Total weight is 800g that can replace 25kg filter sand. It is applicable to most of the pool cleaners of filter, or sand filter pumps in salt water.【Eco-friendly & Durability】Made of 100% polyester fiber, filter balls are light in material, high in air permeability, and has a long service life without repeated washing.【Excellent Filtration】The fiber filter balls are lighter and more efficient than traditional filter sand. Moreover, the filter ball does not block your filter and requires less backwash for maintenance purposes.【Recyclable Usage】High water permeability, lighter, more efficient, excellent filtering, environmentally-friendly and recyclable. Have a long lifespan and save e.