Crystal Quest Countertop Replaceable Single Nitrate Plus Water Filter System Contains a special nitrate-selective resin. Nitrate reduction is 90% to 95% and breakthrough is not affected by sulfate levels. The capacity is 5500 ppm of nitrates as CaCO3. To determine capacity, first calculate the ppm of nitrates as CaCO3, then divide that number into 5500 to get the gallons. This cartridge can be regenerated using sodium chloride brine. A diverter valve switches between filtered and unfiltered water. Adjustable spout for more convenience. Designed in an attractive white housing. Sits on the counter and easily connects to most kitchen faucet. Dimensions: 5"L x 13"H x 5"W