No pumping, no electricity, no moving parts. The Katadyn Ceradyn Drip Water Microfilter is a free-standing, gravity filter with 3 silver impregnated ceramic filters. Confidently treat larger quantities of water with the attachable 2.5 gallon water container. Let gravity do the work! The Katadyn Ceradyn removes harmful bacteria & protazoa (like Giardia and Cryptosporidium) from your drinking water. This Drip filter is used by international relief organizations as group equipment for preparing water. It is also ideal for use while hunting, fishing, at the cabins and in a stabilized emergency situation.