Faucet Mount Water Filter, Reduces Microbiological Cysts Pur 2-Stage Faucet Mount Filtering Unit provides delicious water right from your tap at a fraction of the cost of bottled water. Advanced performance reduces lead and 99.97 percent of the microbiological cysts cryptosporidium and giardia, while leaving beneficial fluoride in the water. Installs easily in minutes on all standard faucets without tools. Offers a bypass feature that easily switches to unfiltered water for washing dishes. Conveniently provides up to 100 gallons (two to three months) of quality water, right from your tap, with easy-to-change replacement filters. Built-in Automatic Safety Monitor gauge shows how much filter life is left and automatically shows you when to replace it.