UDF granular filter cartridge introduction: 1. the fiter is made from nut-shell carbon or coconut carbon 2. Inner diameter : 28mm 3. Outer diameter:70mm 4.micron:5u 5.length:10" 6. the carbon block filter cartrdige is usually used into chemical ,electroplate liquid, papermaking, printing and dyeing, coating, solvents, abstergent, medicine water, purified water, beverage, wines industry and air purification industry. 7.the filter cartrdige can absorb discoloration and peculiar smell in water 25pcs/carton 15kg