Replacement filter element for the Katadyn Guide, PUR Guide and PUR Scout Purifier. - Anti-clog, pleated glass-fiber element has over 140 sq. in. of filtering surface area; 0.3 micron screens particles, protozoa and bacteria - Katadyn Guide fits PUR Guide filters and PUR Scout purifier - Note: This element used in a Scout Purifier will not provide purification, only filtration