This Royal Berkey® System comes standard with 2 Black Berkey® Filtration Elements but can be expanded up to 4 elements The versatile Royal Berkey® System is ideal for use at home with medium-sized families, travel, outdoor activities, or during unexpected emergencies Constructed of highly polished AISI 304 stainless steel Storage capacity of about 3.25 gallons (12.3 liters) Upper chamber nests within lower chamber for transport and stands only 15.25" in height Maximum Filters: 4 Black Berkey® Filtration Elements (in upper chamber) System includes upper and lower stainless steel chamber, 2 Black Berkey® Purification Elements (expandable up to 4), 1 stainless steel lid, 1 spigot, 2 wingnuts, 2 washers, 1 priming button, 2 blocking plugs, 1 rubber gasket to protect the base Height when in use: 23" Diameter: 9.5" Weight: 8 lbs empty For normal everyday use, this system easily serves: 2-4 people Fully configured, this system can serve up to 100-200 people a day, during an emergency Maximum Filtration Flow Rate: Configured with 2 Black Berkey® Purification Elements, the Royal Berkey® System can filter up to 4 gallons (15.1 liters) per hour Configured with 4 Black Berkey® Purification Elements, the Royal Berkey® System can filter up to 7 gallons ( 26.5 liters) per hour Up to 4 PF-2 Berkey PF-2™ Fluoride and Arsenic Elements can be installed in the lower chamber if desired Flow rate calculated with upper chamber full to top. Flow rate decreases as water level declines. Berkey Dimensions Travel Berkey 1.5 GAL 7.5 IN Dia 18 IN High Big Berkey 2.25 GAL 8.5 IN Dia 19.25 IN High Royal Berkey 3.25 GAL 9.5 IN Dia 23 IN High Imperial Berkey 4.5 GAL 10 IN Dia 25.75 IN High Crown Berkey 6 GAL 11 IN Dia 30 IN High