... In the filtration process, filter layer along the flow direction of the gap became smaller and smaller ... distribution of small,it has the following advantages: high efficiency ,filtration rate ,fast, sewage interception capacity, ... ,25-30mmporosity96%Ball AppearanceA white oval-shaped ball Common specifications: 20mm /40mm/20-40mm/ 20-50mm ... soon. fiber-ball filter of high quality and have current goods