ProPur ProBlack-D High Preformance Dome Filter - One Water Filter Includes One ProPur Dome Filter which has a lifespan of 3,000 gallons. Includes One ProPur Dome Filter which has a lifespan of 3,000 gallons. Dome Filter Fits All ProPur Units, but only ProPur Units Dome Filter Fits All ProPur Units, but only ProPur Units Pore size of 0.3 Microns filter out Pathogenic Bacteria Cysts Sediment & etc. Pore size of 0.3 Microns filter out Pathogenic Bacteria Cysts Sediment & etc. NSF-42 certified NSF-42 certified Dome Filter is easy to clean & NO PRIMING REQUIRED! Dome Filter is easy to clean & NO PRIMING REQUIRED!