Set of 4 filter cartridges for gravity water filter. The cartridges are compatible with Berkey and Berkefeld water filters. Tested in France, our gravity water filter cartridges eliminate 99.999% of bacteria and impurities, providing you with pure, healthy, and tasty water. Details: - Materials: Activated carbon - Dimensions: 6D x 13W x 25H Features: - Optimal filtration - Eliminates up to 99.999% of bacteria How to use the filter cartridges: - Ensure you have a gravity water filter - Install the filter cartridges in the upper reservoir - Pour water into the upper reservoir - Wait for all the water to flow into the lower reservoir - Drink filtered water! 1% of our revenue is donated to our partner NGO working for reforestation in the Amazon.