This twin pack of refrigerator filters, compatible with Whirlpool brands, is a welcome addition to any family looking to protect itself against harmful chemicals or particulates that may be present in the private or municipal water supply. The filtration system is composed of a carbon cylinder derived from organic coconut shell compounds. It is riddled with millions of micro-pores that keep hydrophobic particles like lead, zinc, asbestos, hydrogen sulfide, or chlorine out of your drinking water. It allows beneficial hydrophilic particles, those sometimes found in water like Calcium or Sodium, into your glass. Between the two of these filters, you can rest assured that your family will enjoy improved health for up to a year.