PUR FM3333 Pur Water Purification Water filter reduces microbiological cysts like cryptosporidium and giardia. Lessens lead lindane atrazine mercury benzene asbestos chlorine and sediment. Leaves Beneficial Fluoride in the water. Automatic safety monitor shuts off when filter needs replacement. Each filter provides up to 100 gallons (2-3 months) of quality water. 1 EA