The Microfilter K3 1 Micron Carbon Block Inline Water Filter is a high quality inline water filter that is a suitable replacement for refrigerators, under sink filter systems, water fountains, water coolers and more. With a high quality 1 micron coconut carbon block core, the filter is NSF 42 certified for the reduction of chlorine, tastes and odours, leaving you to enjoy fresh tasting water on demand. Each filter meets stringent quality tests to ensure it meets high quality water purification standards.