[Ultra-long service life] When used with municipal water, each undersink water filter has a maximum service life of 36 months or 19,000 gallons. (This may vary based on water conditions.) [Innovative five-stage filtration] Waterdrop Quick Connect Undersink Water Filtration System uses innovative five-stage filtration. Tested against NSF standards, this undersink water filtration system removes 99% of chlorine, heavy metals (including lead, mercury, and arsenic), and chemical contaminants such as fluoride. This undersink filtration system also filters out sediment and other large particles, thereby preventing scale buildup. Enjoy healthy and pure water straight from your tap! [Premium dedicated faucet] The undersink water filtration system comes with a lead-free brushed stainless steel faucet. For separate faucet you already have, WD-15UC system would be a better choice if you want to install it to the separate faucet you already have.